That's what the issue tracker is for. If someone notices a subtle difference and they want it added they'll file an issue. If nobody notices the untested space it doesn't matter.

Maybe we should start with something easy and clone Nethack by just playing it through..

Astra Max can do 12%: https://balrogai.com/

Though after improving the harness it can fare better, but still no completion: https://roger-creus.github.io/blog/astra-craftax-nethack/