diff --git a/Makefile b/Makefile
index 6c4e4fd..e19721a 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-.PHONY: help run build preview aggregate aggregate-repo test-aggregate-local clean clean-projects clean-aggregated-git test test-unit test-integration check spelling linkcheck woke
+.PHONY: help run build preview aggregate aggregate-repo aggregate-update-repo aggregate-repo-single aggregate-update-repo-single test-aggregate-local clean clean-projects clean-aggregated-git test test-unit test-integration check spelling linkcheck woke
 
 help:
 	@echo "Garden Linux Documentation Hub - Available targets:"
@@ -23,8 +23,10 @@ help:
 	@echo "    aggregate-local        - Aggregate from local repos (file:// URLs in repos-config.local.json)"
 	@echo "    aggregate              - Aggregate from locked commits (repos-config.json)"
 	@echo "    aggregate-update       - Fetch latest from remotes and update commit locks"
-	@echo "    aggregate-repo         - Aggregate single repo (usage: make aggregate-repo REPO=gardenlinux)"
-	@echo "    aggregate-update-repo  - Update single repo to latest (usage: make aggregate-update-repo REPO=gardenlinux)"
+	@echo "    aggregate-repo         - Aggregate all repos, overrides scoped to REPO (usage: make aggregate-repo REPO=gardenlinux [REF=branch] [COMMIT=hash])"
+	@echo "    aggregate-update-repo  - Same as aggregate-repo plus update commit locks"
+	@echo "    aggregate-repo-single       - Aggregate only REPO (usage: make aggregate-repo-single REPO=gardenlinux [REF=branch] [COMMIT=hash])"
+	@echo "    aggregate-update-repo-single - Aggregate only REPO and update its commit lock (same optional REF/COMMIT)"
 	@echo ""
 	@echo "  Utilities:"
 	@echo "    clean                  - Clean aggregated docs and build artifacts"
@@ -90,20 +92,46 @@ aggregate-update:
 aggregate-repo:
 	@if [ -z "$(REPO)" ]; then \
 		echo "Error: REPO variable not set"; \
-		echo "Usage: make aggregate-repo REPO=gardenlinux"; \
+		echo "Usage: make aggregate-repo REPO=gardenlinux [REF=branch] [COMMIT=hash]"; \
 		exit 1; \
 	fi
-	@echo "Aggregating documentation for locked repository: $(REPO)"
-	python3 src/aggregate.py --repo $(REPO)
+	@echo "Aggregating all repositories with overrides scoped to: $(REPO)"
+	python3 src/aggregate.py --repo $(REPO) \
+		$(if $(REF),--override-ref $(REF)) \
+		$(if $(COMMIT),--override-commit $(COMMIT))
 
 aggregate-update-repo:
 	@if [ -z "$(REPO)" ]; then \
 		echo "Error: REPO variable not set"; \
-		echo "Usage: make aggregate-update-repo REPO=gardenlinux"; \
+		echo "Usage: make aggregate-update-repo REPO=gardenlinux [REF=branch] [COMMIT=hash]"; \
 		exit 1; \
 	fi
-	@echo "Aggregating documentation for locked repository: $(REPO)"
-	python3 src/aggregate.py --update-locks --repo $(REPO)
+	@echo "Aggregating all repositories with overrides scoped to: $(REPO) (updating locks)"
+	python3 src/aggregate.py --update-locks --repo $(REPO) \
+		$(if $(REF),--override-ref $(REF)) \
+		$(if $(COMMIT),--override-commit $(COMMIT))
+
+aggregate-repo-single:
+	@if [ -z "$(REPO)" ]; then \
+		echo "Error: REPO variable not set"; \
+		echo "Usage: make aggregate-repo-single REPO=gardenlinux [REF=branch] [COMMIT=hash]"; \
+		exit 1; \
+	fi
+	@echo "Aggregating single repository: $(REPO)"
+	python3 src/aggregate.py --repo $(REPO) --single \
+		$(if $(REF),--override-ref $(REF)) \
+		$(if $(COMMIT),--override-commit $(COMMIT))
+
+aggregate-update-repo-single:
+	@if [ -z "$(REPO)" ]; then \
+		echo "Error: REPO variable not set"; \
+		echo "Usage: make aggregate-update-repo-single REPO=gardenlinux [REF=branch] [COMMIT=hash]"; \
+		exit 1; \
+	fi
+	@echo "Aggregating single repository: $(REPO) (updating lock)"
+	python3 src/aggregate.py --repo $(REPO) --single --update-locks \
+		$(if $(REF),--override-ref $(REF)) \
+		$(if $(COMMIT),--override-commit $(COMMIT))
 
 # Utilities
 clean:
diff --git a/docs/contributing/documentation/adding-repos.md b/docs/contributing/documentation/adding-repos.md
index 1c17cb4..72d3045 100644
--- a/docs/contributing/documentation/adding-repos.md
+++ b/docs/contributing/documentation/adding-repos.md
@@ -152,8 +152,8 @@ ls -la docs/how-to/
 For production, lock to a specific commit:
 
 ```bash
-# This fetches the latest and updates repos-config.json
-make aggregate-update-repo REPO=new-repo
+# This fetches only the new repo and updates repos-config.json with its commit hash
+make aggregate-update-repo-single REPO=new-repo
 ```
 
 Or manually add the commit hash:
diff --git a/docs/contributing/documentation/working-locally.md b/docs/contributing/documentation/working-locally.md
index 75eb8df..f6cb6fc 100644
--- a/docs/contributing/documentation/working-locally.md
+++ b/docs/contributing/documentation/working-locally.md
@@ -102,8 +102,24 @@ This creates a production build in `docs/.vitepress/dist/`.
 
 ### Updating a Single Repository
 
+To re-aggregate only one repository without re-fetching all others:
+
+```bash
+make aggregate-repo-single REPO=gardenlinux
+```
+
+To re-aggregate a single repository at a specific ref or commit:
+
+```bash
+make aggregate-repo-single REPO=gardenlinux REF=feature/my-branch
+make aggregate-repo-single REPO=gardenlinux REF=feature/my-branch COMMIT=abc123def
+```
+
+To apply a ref or commit override to one repository while re-aggregating all
+repos (for example, to test a feature branch across the full docs tree):
+
 ```bash
-make aggregate-repo REPO=gardenlinux
+make aggregate-repo REPO=gardenlinux REF=feature/my-branch
 ```
 
 ### Updating Lock Files
diff --git a/src/aggregate.py b/src/aggregate.py
index e998278..48b8a40 100755
--- a/src/aggregate.py
+++ b/src/aggregate.py
@@ -105,20 +105,23 @@ def main() -> int:
         formatter_class=argparse.RawDescriptionHelpFormatter,
         epilog="""
 Examples:
-  # Aggregate all repositories
+  # Aggregate all repositories (default)
   %(prog)s
 
-  # Aggregate with local config (file:// URLs, no git)
-  %(prog)s --config repos-config.local.json
+  # Aggregate all repositories (explicit)
+  %(prog)s --all
 
-  # Aggregate specific repository
-  %(prog)s --repo gardenlinux
-
-  # Aggregate with ref/commit override (for CI from external repos)
+  # Aggregate all repos, applying overrides to one repo (used in CI)
   %(prog)s --repo gardenlinux --override-ref feature/my-docs --override-commit abc123def
 
-  # Update commit locks (fetch and update config with resolved commit hashes)
+  # Aggregate only a single repository
+  %(prog)s --repo gardenlinux --single
+
+  # Update commit locks for all repos
   %(prog)s --update-locks
+
+  # Update commit lock for a single repo only
+  %(prog)s --repo gardenlinux --single --update-locks
         """,
     )
 
@@ -134,7 +137,7 @@ def main() -> int:
     )
     parser.add_argument(
         "--repo",
-        help="Only aggregate specific repository",
+        help="Scope overrides to this repository; required when --single is used",
     )
     parser.add_argument(
         "--update-locks",
@@ -150,8 +153,26 @@ def main() -> int:
         help="Override commit for the repo specified by --repo",
     )
 
+    mode_group = parser.add_mutually_exclusive_group()
+    mode_group.add_argument(
+        "--all",
+        action="store_true",
+        help="Aggregate all repositories (default behaviour; explicit alias)",
+    )
+    mode_group.add_argument(
+        "--single",
+        action="store_true",
+        help="Aggregate only the repository specified by --repo",
+    )
+
     args = parser.parse_args()
 
+    # Validate argument combinations
+    if args.single and not args.repo:
+        parser.error("--single requires --repo NAME")
+    if (args.override_ref or args.override_commit) and not args.repo:
+        parser.error("--override-ref/--override-commit require --repo NAME")
+
     # Determine script directory
     script_dir = Path(__file__).parent.resolve()
     project_root = script_dir.parent
@@ -174,8 +195,10 @@ def main() -> int:
     print(f"{'='*60}\n")
     print(f"Configuration: {config_path}")
     print(f"Docs directory: {docs_dir}")
-    if args.repo:
-        print(f"Repository filter: {args.repo}")
+    if args.single and args.repo:
+        print(f"Single-repo mode: {args.repo}")
+    elif args.repo:
+        print(f"Override scoped to: {args.repo}")
     if args.update_locks:
         print("Update commit locks: ENABLED")
     print()
@@ -194,7 +217,21 @@ def main() -> int:
                     print(f"Override commit for {repo.name}: {args.override_commit}")
                 break
         else:
-            print(f"WARNING: Repository '{args.repo}' not found for override")
+            parser.error(
+                f"Repository '{args.repo}' not found in config; "
+                "cannot apply --override-ref/--override-commit"
+            )
+    elif args.repo:
+        # --repo without overrides: validate the name exists when --single is used
+        # (filter will silently aggregate nothing if the name is wrong)
+        repo_names = {repo.name for repo in repos}
+        if args.repo not in repo_names:
+            if args.single:
+                parser.error(
+                    f"Repository '{args.repo}' not found in config"
+                )
+            else:
+                print(f"WARNING: Repository '{args.repo}' not found in config")
 
     # Create temporary directory for fetched docs
     with tempfile.TemporaryDirectory() as temp_dir_str:
@@ -211,8 +248,8 @@ def main() -> int:
 
         # Aggregate each repository
         for repo in repos:
-            # Filter by repo if specified
-            if args.repo and repo.name != args.repo:
+            # Filter to a single repo when --single is set
+            if args.single and repo.name != args.repo:
                 continue
 
             success, resolved_commit = aggregate_repo(