I have yet to come up with the perfect implementation of the futility pruning in Mediocre. I ran a 300 game match between four different versions and the only conclusion was it is worth including captures in the futility, and I am already doing that. Using a limited material evaluation versus a full evaluation seems to be pretty much equal in strength.
There are a few more things to try out however, like not pruning pawns advancing to the seventh rank or similar, since they will most likely increase the score quite a bit.
There are also some adjustments to the evaluation that needs to be done. In v0.3 I had only a small bonus for rooks on the seventh rank since I did not check if there were actually pawns there (or opponent king on eight rank). Now in v0.31 I added that check so a rook on seventh should be valued higher than before.
The biggest flaw I found was with the x-ray attacks. A queen running diagonally into an own rook kept getting attack points behind it, this is obviously a bug and will be fixed.
Once I am happy with these things I will give candidate pawns another shot. I will most likely have to run a big test with them turned on and off to see if they are worth the effort in Mediocre. I am not expecting a big improvement from them in any case.