Hi Jim,

I think you might be find the quiescence-hashing interesting.
I had this implementation already stashed in my local git repo, because it didn't bring anything in the NON-NNUE version, but now it does. So I made a branch for it:

https://github.com/olithink/OliThink/tree/hashInQuiescence

First tests show an improvement of 20 ELO in tc=40/30s, more in faster games like >30 ELO in tc=40/16s.