We considered both options but decided to go with 100BB because that is the standard in the poker world. It doesn't make a big difference for these techniques though.

Could you try to run a training with ante included in the pot? I wonder if open-limping would be a viable strategy with some hands. No one knows that and it would be really interesting to find out. Ante should be equal to BB, like it was in WSOP Main Event.

Does Pluribus care about opponent's stack depth? From the examples, it appears stacks were reset after each hand.

Guessing it's because it's most similar to a regular 6max game. Also it should limit lower the number of possible ways to play a hand, less chips means the correct choices are easier, so maybe it's computationally easier

Yeah, my question for the author is if stack depth was relevant for this experiment. In headups, they exhausted the entire tree, in six max, they went to a fixed depth.