Orcaman is a very straightforward implementation (just sharded RW locks and backing maps), but it limits the number of shards to a fixed 32. I wonder what the benchmarks would look like if the shard count were increased to 64, 128, etc.
It potentially still might make a difference due to reduced contention: if we have more shards the chances of two or more goroutines hitting the same shard would be lower. In my mind the only downside to having more shards is the upfront cost, so it might slow down the smallest example only
