Every single time I play against the 19-stone master, he plays two 19-stones right next to my 7s, presumably thinking that that'll leave me with no places to continue from. Perhaps this is just me refusing to play challenge mode but I think this is a fundamental issue with the AI. I have not tested this due to unrelated issues

I'm starting this as a new topic because my previous bug reports were not responded to when I put them in the Feedback topic

I've confirmed the AI does know when stones are immune.

Is the AI choosing to play next to 7-stone even when it could destroy one of your stones? If not, there's no issue -- the AI always prefers to play next to your stones, regardless of stone effects, to reduce your number of valid moves. Note that it also tries to avoid destroying it's own stones, so that may be a cause of confusing behavior.