Hi, I looked into this a little. b25 is exclusively used if you offer solver b25/b100 split, so its def the solvers preferred approach. If you go with b25 you are then meant to do quite a lot of "solver-y" stuff, and the IP response feels a little on the non-human side too, but for all that its prob gonna be the better approach by a smallish margin, allin/chk would poss be better as a fallback option for less experienced players since it's way easier to execute.