diff --git a/docs/plans/b2-profile-overlays.md b/docs/plans/b2-profile-overlays.md
new file mode 100644
index 0000000..a2b72a8
--- /dev/null
+++ b/docs/plans/b2-profile-overlays.md
@@ -0,0 +1,62 @@
+# B2: per-profile plugin-enablement overlays — shipped + measured
+
+_Task: B2 in [system-prompt-profiles-tasks.md](system-prompt-profiles-tasks.md) ·
+2026-07-08 · Depends on C3 findings ([c3-spike-findings.md](c3-spike-findings.md))_
+
+## Pre-check result: `enabledPlugins` DEEP-MERGES
+
+The open item from C3 is resolved empirically (transcript `skill_listing` inspection, two
+headless haiku runs): a `--settings <overlay.json>` file's `enabledPlugins` is merged
+key-by-key into `~/.claude/settings.json` — only the plugins explicitly set `false`
+disappear (baseline 64 skills → 61, exactly the 3 skills of the 2 disabled plugins);
+unlisted plugins and all hooks are unaffected. **Diff-only overlays are safe.**
+
+## Shipped
+
+`~/.claude/profiles/` (see its README.md):
+
+- `cc-os-design.json` — disables rails-ui-component, api-wrapper, invoice-ninja,
+  creative-team, dev-team
+- `client-dev.json` — disables creative-team, invoice-ninja, arch-refactor
+- `brainstorm.json` — disables all 9 coding/client plugins (adds ruby-lsp, codex,
+  git-context, arch-refactor)
+
+Usage: `claude --settings ~/.claude/profiles/<name>.json`. Never combine with a
+`--setting-sources` list that omits `user` (silent plugin/hook drop — see vault note
+`claude-code-setting-sources-silent-plugin-drop`).
+
+## Measured savings (headless haiku, empty dir, 2026-07-08)
+
+| Run | Context tokens | Delta vs baseline |
+|---|---|---|
+| baseline (no overlay) | 29,045 | — |
+| cc-os-design (5 plugins off) | 29,013 | −32 |
+| brainstorm (9 plugins off) | 28,413 | −632 |
+
+**Honest verdict: token savings are marginal.**
+
+## Follow-on: YAGNI tool deny (2026-07-08, same session)
+
+Transcript sweep of all sessions since 2026-06-01 (tool_use counts across
+`~/.claude/projects/**/*.jsonl`): heavy use of Bash (7.7k) / Read (4.2k) / Edit (2.1k) /
+Agent (1.3k) / Write (1.2k); **zero-or-one lifetime calls** to Workflow, Artifact,
+SendUserFile, ReportFindings — all of which ship full schemas up front (not deferred).
+
+Measured (headless haiku, empty dir): disallowing Workflow alone −5,982 tokens
+(its schema ≈ the whole system-prompt text); all four −6,509. A `permissions.deny`
+block in a settings file removes the schemas identically to `--disallowedTools`
+(22,532 vs 22,536).
+
+**Applied globally** to `~/.claude/settings.json`:
+`"permissions": {"deny": ["Workflow", "Artifact", "SendUserFile", "ReportFindings"]}` —
+~6.5k saved every session, no flags needed. Revert by deleting the entry (needed if
+"ultracode"-style Workflow orchestration is ever wanted). This delivers the
+"`--tools` restriction is the real lever" prediction from the assessment; A1/A2's
+remaining value is now just the interactive-Fable confirmation. The assessment's "~4.8k user stack"
+is dominated by hooks/memsearch injection and per-plugin fixed listings, not by the
+skill descriptions the overlays remove — ToolSearch deferral already made plugin
+skills cheap. The remaining value of profiles is **focus** (no irrelevant slash
+commands/agents offered in a brainstorm session), not context cost. This further
+deprioritizes Wave 3 (aliases: trivial, do when friction is felt) and Group D
+(dropped), and shifts remaining token-diet attention to the memsearch injection
+(~1.5–3.9k/session, needs upstream fix — see b3-memsearch-injection-review.md).
diff --git a/docs/plans/system-prompt-profiles-tasks.md b/docs/plans/system-prompt-profiles-tasks.md
index 50a940d..6eccb22 100644
--- a/docs/plans/system-prompt-profiles-tasks.md
+++ b/docs/plans/system-prompt-profiles-tasks.md
@@ -34,7 +34,7 @@ A1 and A3 run in parallel; A2 follows A1.
 | ID | Task | Depends on | Suggested agent |
 |---|---|---|---|
 | B1 | **Split cc-os CLAUDE.md.** ~11k tokens → ~2–3k orientation file + `docs/implementation-status.md` (the append-only changelog moved out, linked not `@`-imported so it loads on demand). Follow `~/servers/proxmox-hermes/docs/claude-md-maintenance.md`: keep it short, pointers over copies, never auto-append. Must preserve: the "keep this file current" contract (redirected to the new doc), plugin naming rule, ADR discipline, OpenSpec workflow. Verify a fresh session still orients correctly. | G0 | sonnet (judgment about what is orientation vs changelog); main-loop review before commit |
-| B2 | **Per-profile plugin enablement.** Design + create settings overlay files (one per profile: e.g. `cc-os-design`, `client-dev`, `brainstorm`) listing `enabledPlugins`; a brainstorm profile drops rails-ui-component / api-wrapper / invoice-ninja / creative-team etc. Resolve where overlays live so they don't fight `bin/refresh-plugins` (open question #3). | B1 (so measured savings are attributable) | sonnet |
+| B2 ✅ (2026-07-08, see [b2-profile-overlays.md](b2-profile-overlays.md) — deep-merge confirmed, 3 overlays shipped to `~/.claude/profiles/`, measured savings marginal: −32 to −632 tokens) | **Per-profile plugin enablement.** Design + create settings overlay files (one per profile: e.g. `cc-os-design`, `client-dev`, `brainstorm`) listing `enabledPlugins`; a brainstorm profile drops rails-ui-component / api-wrapper / invoice-ninja / creative-team etc. Resolve where overlays live so they don't fight `bin/refresh-plugins` (open question #3). | B1 (so measured savings are attributable) | sonnet |
 | B3 | **memsearch injection review.** Measure the SessionStart recall injection size across a week of sessions (~13 KB observed once); review memsearch plugin config options for capping/trimming it; recommend (not apply) a setting. | — (parallel with B1/B2 once G0 clears) | haiku |
 
 ## Group C — `cyolo` profile wrapper (Phase 2, after B)
@@ -63,7 +63,10 @@ A1 and A3 run in parallel; A2 follows A1.
 Superseded by the slimmed scope above. Current order:
 
 1. **Wave 1 (parallel):** B1 (main-loop), B3 + C3 (subagents).
-2. **Wave 2:** B2 (needs C3's overlay-location answer).
+2. **Wave 2:** B2 (needs C3's overlay-location answer). ✅ Done 2026-07-08 —
+   overlays shipped; measured token savings marginal (plugin listings are cheap
+   post-ToolSearch), so profiles' value is focus, not context cost.
 3. **Wave 3 (minimal C):** settings-overlay aliases only; full C1/C2 wrapper deferred
-   until the friction is felt.
+   until the friction is felt. B2's marginal-savings result lowers this further —
+   do only when friction is actually felt.
 4. **Deferred:** A1/A2 pending the interactive `/context` check; D dropped (pointer kept).