diff --git a/src/scripts/resolve_config.py b/src/scripts/resolve_config.py
index 1dada0fc9..1e20b8978 100644
--- a/src/scripts/resolve_config.py
+++ b/src/scripts/resolve_config.py
@@ -227,6 +227,17 @@ def main():
     project_root = Path(args.project_root).resolve() if args.project_root else None
     global_dir = resolve_global_dir()
 
+    # If the caller explicitly named a project root, that's a promise it exists
+    # and has been installed. Fail loudly on a missing _bmad/ rather than
+    # silently returning {} — that masked broken installs in the old required=
+    # True behavior. Global-only mode (no --project-root) stays permissive.
+    if project_root is not None and not (project_root / "_bmad").is_dir():
+        sys.stderr.write(
+            f"error: --project-root {project_root} has no _bmad/ directory "
+            f"(install not present, or wrong path)\n"
+        )
+        sys.exit(1)
+
     merged: dict = {}
     # Floor: per-module shipped defaults (lowest priority).
     for module_toml in collect_module_layers(project_root):
diff --git a/src/scripts/resolve_customization.py b/src/scripts/resolve_customization.py
index 287a5c6a2..23c546803 100755
--- a/src/scripts/resolve_customization.py
+++ b/src/scripts/resolve_customization.py
@@ -197,7 +197,7 @@ def deep_merge(base, override):
     return override
 
 
-_MODULE_SKILLS_RE = re.compile(r"^(?P<module>[A-Za-z0-9_]+)-skills$")
+_MODULE_SKILLS_RE = re.compile(r"^(?P<module>[A-Za-z0-9_-]+)-skills$")
 
 
 def detect_skill_module(skill_dir: Path) -> str | None:
diff --git a/src/scripts/tests/test_resolve_config.py b/src/scripts/tests/test_resolve_config.py
index 8bf3ba055..ab867e05b 100644
--- a/src/scripts/tests/test_resolve_config.py
+++ b/src/scripts/tests/test_resolve_config.py
@@ -10,7 +10,9 @@ from pathlib import Path
 SCRIPT = Path(__file__).resolve().parents[1] / "resolve_config.py"
 
 
-def run(args, env_overrides=None):
+def run_raw(args, env_overrides=None):
+    """Run resolver, return CompletedProcess-like object with decoded streams.
+    Use this when the test expects a non-zero exit (e.g. fail-fast checks)."""
     env = os.environ.copy()
     env["BMAD_HOME"] = env.get("BMAD_HOME", "/nonexistent-bmad-home-default")
     if env_overrides:
@@ -22,10 +24,16 @@ def run(args, env_overrides=None):
         env=env,
         check=False,
     )
-    stderr = result.stderr.decode("utf-8", errors="replace")
+    result.stdout = result.stdout.decode("utf-8", errors="replace")
+    result.stderr = result.stderr.decode("utf-8", errors="replace")
+    return result
+
+
+def run(args, env_overrides=None):
+    result = run_raw(args, env_overrides=env_overrides)
     if result.returncode != 0:
-        raise AssertionError(f"resolve_config failed ({result.returncode}): {stderr}")
-    return json.loads(result.stdout.decode("utf-8"))
+        raise AssertionError(f"resolve_config failed ({result.returncode}): {result.stderr}")
+    return json.loads(result.stdout)
 
 
 class ResolveConfigTests(unittest.TestCase):
@@ -79,11 +87,23 @@ class ResolveConfigTests(unittest.TestCase):
         self.assertEqual(data["core"]["user_name"], "Pinned")
 
     def test_project_config_optional(self):
-        # No _bmad/config.toml; should not error
+        # _bmad/ exists (installed project) but no config.toml inside — that's
+        # the lean / global-only case and must not error.
         with tempfile.TemporaryDirectory() as proj:
+            (Path(proj) / "_bmad").mkdir()
             data = run(["--project-root", proj])
         self.assertEqual(data, {})
 
+    def test_project_root_without_bmad_dir_errors(self):
+        # --project-root pointing at a directory with no _bmad/ is treated
+        # as a broken install (typo, wiped install) — resolver exits non-zero
+        # rather than silently returning {}. Global-only mode (no
+        # --project-root) keeps the permissive behavior.
+        with tempfile.TemporaryDirectory() as proj:
+            result = run_raw(["--project-root", proj])
+        self.assertNotEqual(result.returncode, 0)
+        self.assertIn("no _bmad/ directory", result.stderr)
+
     def test_module_floor_contributes_when_no_overrides(self):
         # Module-shipped defaults from _bmad/{module}/module.toml should
         # appear when nothing else specifies them.
diff --git a/test/test-installation-components.js b/test/test-installation-components.js
index 01a0bd61c..0b19af7b4 100644
--- a/test/test-installation-components.js
+++ b/test/test-installation-components.js
@@ -3027,6 +3027,12 @@ async function runTests() {
   // Test Suite 44: --set <module>.<key>=<value> CLI overrides (#1663)
   // ============================================================
   console.log(`${colors.yellow}Test Suite 44: --set CLI overrides${colors.reset}\n`);
+  // Isolate $BMAD_HOME for the whole suite — applySetOverrides now consults
+  // ~/.bmad/config.user.toml for routing decisions, and we don't want tests
+  // touching the developer's actual global identity.
+  const tempGlobalDir44 = await fs.mkdtemp(path.join(os.tmpdir(), 'bmad-applyset-global-'));
+  const priorBmadHome44 = process.env.BMAD_HOME;
+  process.env.BMAD_HOME = tempGlobalDir44;
   try {
     const { parseSetEntry, parseSetEntries, applySetOverrides, upsertTomlKey, tomlString } = require('../tools/installer/set-overrides');
     const { discoverOfficialModuleYamls, formatOptionsList } = require('../tools/installer/list-options');
@@ -3191,15 +3197,24 @@ async function runTests() {
       await fs.writeFile(path.join(bmadDir, 'config.toml'), '[core]\nuser_name = "Brian"\n', 'utf8');
       await fs.ensureDir(path.join(bmadDir, 'core'));
       await fs.writeFile(path.join(bmadDir, 'core', 'config.yaml'), 'user_name: Brian\n', 'utf8');
-      // Override targets a key only in team config; routes to team. user.toml
-      // never gets created in this case (correct — no user-scope writes).
+      // Override targets a core scope:user key. Per Task D's 3-tier routing,
+      // core.user_name lands in ~/.bmad/config.user.toml regardless of whether
+      // project user.toml exists — that's where the resolver picks it up.
+      // Project files (team and user) are left untouched.
       await applySetOverrides({ core: { user_name: 'Updated' } }, bmadDir);
       const team = await fs.readFile(path.join(bmadDir, 'config.toml'), 'utf8');
-      assert(team.includes('user_name = "Updated"'), 'applySetOverrides updates team key when user.toml is absent');
+      const globalContent = await fs.readFile(path.join(tempGlobalDir44, 'config.user.toml'), 'utf8');
+      assert(
+        globalContent.includes('user_name = "Updated"'),
+        'applySetOverrides routes core.user_name to global when project user.toml is absent',
+      );
+      assert(!team.includes('user_name = "Updated"'), 'applySetOverrides does not write core scope:user keys to project team config');
       assert(
         !(await fs.pathExists(path.join(bmadDir, 'config.user.toml'))),
-        'applySetOverrides does not create config.user.toml unnecessarily',
+        'applySetOverrides does not create project config.user.toml for scope:user core keys',
       );
+      // Reset global file for the next test block.
+      await fs.remove(path.join(tempGlobalDir44, 'config.user.toml')).catch(() => {});
       await fs.remove(tmp).catch(() => {});
     }
 
@@ -3213,11 +3228,17 @@ async function runTests() {
       await fs.writeFile(path.join(bmadDir, 'core', 'config.yaml'), 'user_name: Brian\n', 'utf8');
       // bmm is not installed (no `_bmad/bmm/config.yaml`). The override for
       // bmm should be silently skipped, no `[modules.bmm]` section created.
+      // core.user_name is scope:user → routed to global (~/.bmad).
       const applied = await applySetOverrides({ bmm: { foo: 'bar' }, core: { user_name: 'Updated' } }, bmadDir);
       const team = await fs.readFile(path.join(bmadDir, 'config.toml'), 'utf8');
+      const globalContent = await fs.readFile(path.join(tempGlobalDir44, 'config.user.toml'), 'utf8');
       assert(!team.includes('[modules.bmm]'), 'applySetOverrides does NOT create section for uninstalled module');
-      assert(team.includes('user_name = "Updated"'), 'applySetOverrides still applies overrides for installed modules');
+      assert(
+        globalContent.includes('user_name = "Updated"'),
+        'applySetOverrides still applies overrides for installed modules (routed to global for scope:user core)',
+      );
       assert(applied.length === 1 && applied[0].module === 'core', 'applySetOverrides reports only the installed-module entries');
+      await fs.remove(path.join(tempGlobalDir44, 'config.user.toml')).catch(() => {});
       await fs.remove(tmp).catch(() => {});
     }
 
@@ -3273,6 +3294,13 @@ async function runTests() {
     console.log(`${colors.red}Test Suite 44 setup failed: ${error.message}${colors.reset}`);
     console.log(error.stack);
     failed++;
+  } finally {
+    if (priorBmadHome44 === undefined) {
+      delete process.env.BMAD_HOME;
+    } else {
+      process.env.BMAD_HOME = priorBmadHome44;
+    }
+    await fs.remove(tempGlobalDir44).catch(() => {});
   }
 
   console.log('');
diff --git a/tools/installer/core/manifest-generator.js b/tools/installer/core/manifest-generator.js
index a5194f6e4..a0653f121 100644
--- a/tools/installer/core/manifest-generator.js
+++ b/tools/installer/core/manifest-generator.js
@@ -459,9 +459,17 @@ class ManifestGenerator {
     //   1. scope per prompt key (team vs user)
     //   2. the canonical module code (for [modules.{code}] section names)
     //   3. processed defaults per key (for delta detection)
+    //
+    // Pass 1: parse every module.yaml and capture its raw shipped defaults.
+    // We use those — NOT the user's answered moduleConfigs — to resolve
+    // cross-key placeholders like `{output_folder}`. Otherwise a user override
+    // of output_folder would make every derived default (e.g. planning_artifacts)
+    // match the user's value and get stripped from config.toml as "default",
+    // even though module.toml's floor still carries the shipped path.
     const scopeByModuleKey = {};
     const codeByModuleName = {};
     const defaultsByModuleKey = {};
+    const parsedByModule = {};
     for (const moduleName of this.updatedModules) {
       const moduleYamlPath = await resolveInstalledModuleYaml(moduleName);
       if (!moduleYamlPath) {
@@ -474,17 +482,8 @@ class ManifestGenerator {
       try {
         const parsed = yaml.parse(await fs.readFile(moduleYamlPath, 'utf8'));
         if (!parsed || typeof parsed !== 'object') continue;
+        parsedByModule[moduleName] = parsed;
         if (parsed.code) codeByModuleName[moduleName] = parsed.code;
-        scopeByModuleKey[moduleName] = {};
-        defaultsByModuleKey[moduleName] = {};
-        for (const [key, value] of Object.entries(parsed)) {
-          if (!value || typeof value !== 'object' || !('prompt' in value)) continue;
-          scopeByModuleKey[moduleName][key] = value.scope === 'user' ? 'user' : 'team';
-          const processedDefault = computeProcessedDefault(value, moduleConfigs);
-          if (processedDefault !== undefined) {
-            defaultsByModuleKey[moduleName][key] = processedDefault;
-          }
-        }
       } catch (error) {
         console.warn(
           `[warn] writeCentralConfig: could not parse module.yaml for '${moduleName}' (${error.message}). ` +
@@ -493,6 +492,35 @@ class ManifestGenerator {
       }
     }
 
+    // Build the cross-key defaults map (same logic writeModuleTomls uses).
+    // Shipped defaults only — never user answers.
+    const crossKeyDefaults = {};
+    for (const parsed of Object.values(parsedByModule)) {
+      const raw = extractModuleDefaults(parsed);
+      for (const [key, value] of Object.entries(raw)) {
+        if (crossKeyDefaults[key] !== undefined) continue;
+        let stripped = value;
+        if (typeof stripped === 'string' && stripped.startsWith('{project-root}/')) {
+          stripped = stripped.slice('{project-root}/'.length);
+        }
+        crossKeyDefaults[key] = stripped;
+      }
+    }
+
+    // Pass 2: compute scopes and processed defaults using the symmetric map.
+    for (const [moduleName, parsed] of Object.entries(parsedByModule)) {
+      scopeByModuleKey[moduleName] = {};
+      defaultsByModuleKey[moduleName] = {};
+      for (const [key, value] of Object.entries(parsed)) {
+        if (!value || typeof value !== 'object' || !('prompt' in value)) continue;
+        scopeByModuleKey[moduleName][key] = value.scope === 'user' ? 'user' : 'team';
+        const processedDefault = computeProcessedDefault(value, crossKeyDefaults);
+        if (processedDefault !== undefined) {
+          defaultsByModuleKey[moduleName][key] = processedDefault;
+        }
+      }
+    }
+
     // Load the global config snapshot for [core] delta detection. If a key's
     // current value equals the global value, no need to duplicate it into the
     // project file — the resolver finds it globally.
@@ -702,15 +730,10 @@ class ManifestGenerator {
       '# ─────────────────────────────────────────────────────────────────',
       '',
     ];
-    for (const [section, table] of Object.entries(mergedConfig)) {
-      if (!table || typeof table !== 'object' || Array.isArray(table)) continue;
-      lines.push(`[${section}]`);
-      for (const [key, value] of Object.entries(table)) {
-        if (value === undefined || value === null || value === '') continue;
-        lines.push(`${key} = ${formatTomlValue(value)}`);
-      }
-      lines.push('');
-    }
+    // Emit sections recursively so nested tables (e.g. [modules.bmm] reachable
+    // via dotted parseSimpleToml output) round-trip as proper sub-tables
+    // instead of being stringified as "[object Object]" inside their parent.
+    emitTomlSections(mergedConfig, [], lines);
     const content = lines.join('\n').replace(/\n+$/, '\n');
     await fs.writeFile(globalPath, content);
     return globalPath;
@@ -1019,25 +1042,27 @@ class ManifestGenerator {
  * Objects are not expected at this emit path.
  */
 /**
- * Compute the processed default value for a module.yaml question item, using
- * the already-resolved moduleConfigs map for cross-key references like
- * `{output_folder}`. Used by writeCentralConfig to detect default-equal
- * values that should NOT be re-emitted into the lean config.toml.
+ * Compute the processed default value for a module.yaml question item.
+ * Resolves `{key}` cross-references against the flat `crossKeyDefaults` lookup
+ * (shipped defaults, never user answers — see writeCentralConfig comment).
+ * Used by writeCentralConfig to detect default-equal values that should NOT
+ * be re-emitted into the lean config.toml. Matches the lookup table that
+ * writeModuleTomls uses, so module.toml's floor and config.toml's delta
+ * detection agree on what "default" means.
  *
  * Steps:
- *   1. Substitute {key} references against any module's already-collected
- *      value (with leading "{project-root}/" stripped, matching the
- *      installer's processResultTemplate behavior).
+ *   1. Substitute {key} references against crossKeyDefaults (with leading
+ *      "{project-root}/" stripped, matching the installer's
+ *      processResultTemplate behavior).
  *   2. Apply the result: template with {value} substituted.
  *
- * Returns undefined for items without a default, leaving the caller's delta
- * check to fall through unchanged.
+ * Returns undefined for items without a default.
  *
  * @param {object} item - one module.yaml question schema
- * @param {object} moduleConfigs - already-resolved per-module configs
+ * @param {Record<string, *>} crossKeyDefaults - flat shipped-defaults lookup
  * @returns {*} processed default value (string/scalar) or undefined
  */
-function computeProcessedDefault(item, moduleConfigs) {
+function computeProcessedDefault(item, crossKeyDefaults) {
   if (!item || item.default === undefined || item.default === null) return;
   let value = item.default;
   if (typeof value === 'string') {
@@ -1045,16 +1070,8 @@ function computeProcessedDefault(item, moduleConfigs) {
       if (refKey === 'project-root' || refKey === 'value' || refKey === 'directory_name') {
         return match;
       }
-      for (const mod of Object.values(moduleConfigs || {})) {
-        if (mod && typeof mod === 'object' && mod[refKey] !== undefined) {
-          let resolved = mod[refKey];
-          if (typeof resolved === 'string' && resolved.startsWith('{project-root}/')) {
-            resolved = resolved.slice('{project-root}/'.length);
-          }
-          return resolved;
-        }
-      }
-      return match;
+      const replacement = (crossKeyDefaults || {})[refKey];
+      return replacement === undefined ? match : String(replacement);
     });
   }
   if (typeof item.result === 'string' && value !== undefined) {
@@ -1163,39 +1180,26 @@ function formatTomlValue(value) {
   return `"${escaped}"`;
 }
 
-/**
- * Extract [agents.<code>] blocks from a previously-emitted config.toml.
- * We only need this for roster preservation — the file is our own controlled
- * output, so a simple line scanner is safer than adding a TOML parser
- * dependency. Each block runs from its `[agents.<code>]` header until the
- * next `[` heading or EOF; the `module = "..."` line inside drives which
- * entries we keep on the next write.
- * @returns {Array<{code: string, module: string | null, body: string}>}
- */
-function extractAgentBlocks(tomlContent) {
-  const blocks = [];
-  const lines = tomlContent.split('\n');
-  let i = 0;
-  while (i < lines.length) {
-    const header = lines[i].match(/^\[agents\.([^\]]+)]\s*$/);
-    if (!header) {
-      i++;
-      continue;
+// Recursively serialize a parsed TOML object back to text. Scalar entries
+// are written under the current section header; nested objects are emitted
+// as dotted sub-tables. Skips null/undefined/'' values.
+function emitTomlSections(node, sectionPath, lines) {
+  const scalars = [];
+  const nested = [];
+  for (const [key, value] of Object.entries(node)) {
+    if (value === null || value === undefined || value === '') continue;
+    if (value && typeof value === 'object' && !Array.isArray(value)) {
+      nested.push([key, value]);
+    } else {
+      scalars.push([key, value]);
     }
-    const code = header[1];
-    const blockLines = [lines[i]];
-    let moduleName = null;
-    i++;
-    while (i < lines.length && !lines[i].startsWith('[')) {
-      blockLines.push(lines[i]);
-      const m = lines[i].match(/^module\s*=\s*"((?:[^"\\]|\\.)*)"\s*$/);
-      if (m) moduleName = m[1];
-      i++;
-    }
-    while (blockLines.length > 1 && blockLines.at(-1) === '') blockLines.pop();
-    blocks.push({ code, module: moduleName, body: blockLines.join('\n') });
   }
-  return blocks;
+  if (scalars.length > 0) {
+    if (sectionPath.length > 0) lines.push(`[${sectionPath.join('.')}]`);
+    for (const [key, value] of scalars) lines.push(`${key} = ${formatTomlValue(value)}`);
+    lines.push('');
+  }
+  for (const [key, value] of nested) emitTomlSections(value, [...sectionPath, key], lines);
 }
 
 module.exports = { ManifestGenerator };
diff --git a/tools/installer/global-config.js b/tools/installer/global-config.js
index d79fc5efb..aee0a5337 100644
--- a/tools/installer/global-config.js
+++ b/tools/installer/global-config.js
@@ -22,11 +22,22 @@ const fs = require('./fs-native');
 function resolveGlobalDir() {
   const override = process.env.BMAD_HOME;
   if (override && override.trim()) {
-    return path.resolve(override.trim());
+    return path.resolve(expandTilde(override.trim()));
   }
   return path.join(os.homedir(), '.bmad');
 }
 
+// JS counterpart to Python's Path.expanduser() — keeps installer/resolver
+// agreement when BMAD_HOME is set in non-shell contexts (Docker, .env files,
+// Windows env var GUI) where the shell never expands `~`.
+function expandTilde(input) {
+  if (input === '~') return os.homedir();
+  if (input.startsWith('~/') || input.startsWith('~\\')) {
+    return path.join(os.homedir(), input.slice(2));
+  }
+  return input;
+}
+
 function globalTeamConfigPath() {
   return path.join(resolveGlobalDir(), 'config.toml');
 }
@@ -111,13 +122,11 @@ function stripInlineComment(line) {
 
 function parseTomlScalar(raw) {
   if (raw.startsWith('"') && raw.endsWith('"') && raw.length >= 2) {
-    return raw
-      .slice(1, -1)
-      .replaceAll(String.raw`\"`, '"')
-      .replaceAll(String.raw`\\`, '\\')
-      .replaceAll(String.raw`\n`, '\n')
-      .replaceAll(String.raw`\r`, '\r')
-      .replaceAll(String.raw`\t`, '\t');
+    // Single-pass unescape — sequential replaceAll lets `\\n` (backslash + n)
+    // collapse into a newline because the second pass sees the just-produced
+    // `\n` and treats it as the escape sequence. One regex avoids that.
+    const escapes = { '\\\\': '\\', '\\"': '"', '\\n': '\n', '\\r': '\r', '\\t': '\t' };
+    return raw.slice(1, -1).replaceAll(/\\["\\nrt]/g, (m) => escapes[m] ?? m);
   }
   if (raw === 'true') return true;
   if (raw === 'false') return false;
diff --git a/tools/installer/modules/official-modules.js b/tools/installer/modules/official-modules.js
index a9ba68125..d2f22f010 100644
--- a/tools/installer/modules/official-modules.js
+++ b/tools/installer/modules/official-modules.js
@@ -1144,6 +1144,18 @@ class OfficialModules {
     if (!this._existingConfig) {
       await this.loadExistingConfig(projectDir);
     }
+    // Lazy-load global config so identity fallbacks below can consult
+    // ~/.bmad/config.user.toml. quickUpdate doesn't go through
+    // collectAllConfigurations, so this.globalConfig would otherwise be unset
+    // and user_name would silently default to the OS username — overwriting
+    // the value the user previously committed to global.
+    if (!this.globalConfig) {
+      try {
+        this.globalConfig = await loadGlobalConfig();
+      } catch {
+        this.globalConfig = { merged: {} };
+      }
+    }
 
     // Initialize allAnswers if not already initialized
     if (!this.allAnswers) {
@@ -1220,12 +1232,14 @@ class OfficialModules {
         }
         this.collectedConfig[moduleName] = { ...this._existingConfig[moduleName] };
 
-        // Special handling for user_name: ensure it has a value
+        // Special handling for user_name: ensure it has a value. Prefer the
+        // global value (~/.bmad/config.user.toml) before the OS username, or
+        // we'll silently overwrite the user's prior global identity.
         if (
           moduleName === 'core' &&
           (!this.collectedConfig[moduleName].user_name || this.collectedConfig[moduleName].user_name === '[USER_NAME]')
         ) {
-          this.collectedConfig[moduleName].user_name = this.getDefaultUsername();
+          this.collectedConfig[moduleName].user_name = this._identityFallback('user_name');
         }
 
         // Also populate allAnswers for cross-referencing
@@ -1233,18 +1247,20 @@ class OfficialModules {
           // Ensure user_name is properly set in allAnswers too
           let finalValue = value;
           if (moduleName === 'core' && key === 'user_name' && (!value || value === '[USER_NAME]')) {
-            finalValue = this.getDefaultUsername();
+            finalValue = this._identityFallback('user_name');
           }
           this.allAnswers[`${moduleName}_${key}`] = finalValue;
         }
       } else if (moduleName === 'core') {
-        // No existing core config - ensure we at least have user_name
+        // No existing core config - ensure we at least have user_name.
+        // Same global-first preference as above.
         if (!this.collectedConfig[moduleName]) {
           this.collectedConfig[moduleName] = {};
         }
         if (!this.collectedConfig[moduleName].user_name) {
-          this.collectedConfig[moduleName].user_name = this.getDefaultUsername();
-          this.allAnswers[`${moduleName}_user_name`] = this.getDefaultUsername();
+          const fallback = this._identityFallback('user_name');
+          this.collectedConfig[moduleName].user_name = fallback;
+          this.allAnswers[`${moduleName}_user_name`] = fallback;
         }
       }
 
@@ -1422,6 +1438,22 @@ class OfficialModules {
     return result;
   }
 
+  /**
+   * Fall back through identity sources for a core scope:user key. Prefers the
+   * global value (~/.bmad/config.user.toml) so quickUpdate / re-install never
+   * silently overwrites a previously-set identity with the OS username.
+   * Only user_name has an OS-derived ultimate fallback; other keys return
+   * undefined so the caller can decide.
+   */
+  _identityFallback(key) {
+    const globalCore = (this.globalConfig && this.globalConfig.merged && this.globalConfig.merged.core) || {};
+    if (globalCore[key] !== undefined && globalCore[key] !== '' && globalCore[key] !== null) {
+      return globalCore[key];
+    }
+    if (key === 'user_name') return this.getDefaultUsername();
+    return;
+  }
+
   /**
    * Collect configuration for a single module
    * @param {string} moduleName - Module name
@@ -1932,9 +1964,10 @@ class OfficialModules {
       existingValue = this.normalizeExistingValueForPrompt(existingValue, moduleName, item, moduleConfig);
     }
 
-    // Special handling for user_name: default to system user
+    // Special handling for user_name: prefer global identity (~/.bmad) over
+    // OS username so the prompt's default reflects what the user already chose.
     if (moduleName === 'core' && key === 'user_name' && !existingValue) {
-      item.default = this.getDefaultUsername();
+      item.default = this._identityFallback('user_name');
     }
 
     // Determine question type and default value
diff --git a/tools/installer/set-overrides.js b/tools/installer/set-overrides.js
index 9349ee2d6..24815346a 100644
--- a/tools/installer/set-overrides.js
+++ b/tools/installer/set-overrides.js
@@ -25,6 +25,8 @@ const PROTOTYPE_POLLUTING_NAMES = new Set(['__proto__', 'prototype', 'constructo
 const path = require('node:path');
 const fs = require('./fs-native');
 const yaml = require('yaml');
+const { globalUserConfigPath } = require('./global-config');
+const { resolveInstalledModuleYaml } = require('./project-root');
 
 /**
  * Parse a single `--set <module>.<key>=<value>` entry.
@@ -215,19 +217,49 @@ async function tomlHasKey(filePath, section, key) {
   return false;
 }
 
+/**
+ * Look up which prompt keys in `core/module.yaml` are declared `scope: user`.
+ * Used so `--set` routes core scope:user keys (user_name, communication_language)
+ * to the global identity file the installer's writeGlobalUserCore writes to,
+ * rather than polluting project config.toml as a team-scope key.
+ * Returns an empty set if core isn't installed or the schema can't be parsed.
+ */
+async function loadCoreUserScopeKeys() {
+  const result = new Set();
+  try {
+    const corePath = await resolveInstalledModuleYaml('core');
+    if (!corePath) return result;
+    const parsed = yaml.parse(await fs.readFile(corePath, 'utf8'));
+    if (!parsed || typeof parsed !== 'object') return result;
+    for (const [key, value] of Object.entries(parsed)) {
+      if (value && typeof value === 'object' && 'prompt' in value && value.scope === 'user') {
+        result.add(key);
+      }
+    }
+  } catch {
+    // Schema unavailable — fall back to two-tier routing.
+  }
+  return result;
+}
+
 /**
  * Apply parsed `--set` overrides to the central TOML files written by the
  * installer. Called at the end of an install / quick-update.
  *
  * Routing per (module, key):
- *   1. If `_bmad/config.user.toml` already has `[section] key`, update there
- *      (user-scope key like `core.user_name`, `bmm.user_skill_level`).
- *   2. Otherwise update `_bmad/config.toml` (team scope, the default).
+ *   1. If `~/.bmad/config.user.toml` already has `[section] key`, update there
+ *      (global identity store — same place writeGlobalUserCore writes to).
+ *   2. Else if `_bmad/config.user.toml` already has `[section] key`, update
+ *      there (project-scoped personal override).
+ *   3. Else if the key is a known core scope:user key (user_name,
+ *      communication_language per core/module.yaml), route to global. Otherwise
+ *      writeCentralConfig's next-install partition would strip the value out
+ *      of project files.
+ *   4. Otherwise update `_bmad/config.toml` (team scope, the default).
  *
- * The schema-correct user/team partition lives in `manifest-generator`. We
- * intentionally don't re-read module schemas here — the only goal is to
- * match the file the installer just wrote the key to. For brand-new keys
- * (not in either file yet), team scope is the safe default.
+ * The schema-correct partition lives in `manifest-generator`. We only reach
+ * for the core schema (small, always present) so the first-run case for
+ * `--set core.user_name=...` doesn't land in the wrong file.
  *
  * @param {Object<string, Object<string, string>>} overrides
  * @param {string} bmadDir absolute path to `_bmad/`
@@ -240,6 +272,8 @@ async function applySetOverrides(overrides, bmadDir) {
 
   const teamPath = path.join(bmadDir, 'config.toml');
   const userPath = path.join(bmadDir, 'config.user.toml');
+  const globalPath = globalUserConfigPath();
+  const coreUserKeys = await loadCoreUserScopeKeys();
 
   for (const moduleCode of Object.keys(overrides)) {
     // Skip overrides for modules not actually installed. The installer writes
@@ -258,16 +292,35 @@ async function applySetOverrides(overrides, bmadDir) {
       const value = moduleOverrides[key];
       const valueToml = tomlString(value);
 
-      const userOwnsIt = await tomlHasKey(userPath, section, key);
-      const targetPath = userOwnsIt ? userPath : teamPath;
+      // 3-tier routing: prefer the file that already owns the key; otherwise
+      // honor core's user-scope partition (so `--set core.user_name` lands in
+      // ~/.bmad on a fresh install, not in project team config).
+      const globalOwnsIt = moduleCode === 'core' && (await tomlHasKey(globalPath, section, key));
+      const userOwnsIt = !globalOwnsIt && (await tomlHasKey(userPath, section, key));
+      const isCoreUserScope = moduleCode === 'core' && coreUserKeys.has(key) && !userOwnsIt;
+      let targetPath;
+      let scope;
+      if (globalOwnsIt || isCoreUserScope) {
+        targetPath = globalPath;
+        scope = 'user';
+      } else if (userOwnsIt) {
+        targetPath = userPath;
+        scope = 'user';
+      } else {
+        targetPath = teamPath;
+        scope = 'team';
+      }
 
-      // The team file always exists post-install; the user file only exists
-      // if the install wrote at least one user-scope key. If we're routing to
-      // it but it doesn't exist yet, create it with a minimal header so it
-      // has the same shape as installer-written user toml.
+      // The team file always exists post-install; the user/global files only
+      // exist once the installer has reason to write to them. If we're routing
+      // to one that doesn't exist yet, create it with a minimal header so it
+      // has the same shape as installer-written files.
       let content = '';
       if (await fs.pathExists(targetPath)) {
         content = await fs.readFile(targetPath, 'utf8');
+      } else if (targetPath === globalPath) {
+        await fs.ensureDir(path.dirname(globalPath));
+        content = '# Global personal BMad config (see ~/.bmad).\n';
       } else {
         content = '# Personal overrides for _bmad/config.toml.\n';
       }
@@ -277,8 +330,8 @@ async function applySetOverrides(overrides, bmadDir) {
       applied.push({
         module: moduleCode,
         key,
-        scope: userOwnsIt ? 'user' : 'team',
-        file: path.basename(targetPath),
+        scope,
+        file: targetPath === globalPath ? '~/.bmad/config.user.toml' : path.basename(targetPath),
       });
     }