Since you're in here, if I can recommend: sync.Pool with non-fixed-size objects is a source of many problems. https://wundergraph.com/blog/golang-sync-pool as a decent overview, and https://github.com/yarpc/yarpc-go/issues/2355 has been my recent plague.

If you browse around Go's stdlib use of sync.Pool, you'll see a variety of tiered pools with fixed sizes, and many drop anything over a large enough size (sometimes gigantic! as much as 16KB!): https://cs.opensource.google/go/go/+/refs/tags/go1.24.0:src/...

It's a pretty well-established gotcha, sadly, and https://github.com/teivah/100-go-mistakes/blob/master/src/12... falls right into it.