well the monk's fists are actual weapons you can find with shadowkeeper or even clua in, i cant recall the name of them, but its something like mfist01 - mfist06 or similar. If i had bg2 installed right now id open them up with IEEP and take a look for you. But i suspect that the number of attacks is stored in the actual ITM file. (maybe the ac too)
Ah yes you could be correct. I found MFIST01 - MFIST08 so that could account for attacks per round... but not for ac as that would require more items I believe.