Exposes the pick_independent instance field (engine resolution landed in 33b3600): instance schema + snapshot round-trip, TS instance type + _shell INSTANCE_FIELDS_PER_KIND registry (so reset-overrides + modified-state + the TS/Py parity gate all include it) + preview cache-key, and the canvas PoolSection 'Allow repeats' toggle (shown only while multi-pick is active; off = unique). Instance-only (per-node, canvas runtime), additive + tolerant — no community catalog change.