One thing I'm worried about with scapegoat mechanics is it may make characters reluctant to point fingers (even if everyone's fine with it ooc) which is already a little bit of a problem in meetings, because suddenly getting it wrong has consequences. This is not in and of itself bad but means that the consequence for just... not trying to catch anyone at all and letting the murder stand needs to be higher to push back against that inertia, which is why death games so often have 'everyone will die if you don't pick someone'.

Making it something more external and less of an ic choice could work... something like even if you didn't do it the accumulated karma of suspicion sort of 'sticks' to you until it's cleared, and if it goes on too long/gets strong enough it can start causing effects? Or something meted out by the school itself... Not sure.

EDIT: Also seconding reduced prices on Bonus AC... I'm crying bc I do think plot clues could stand to be a little cheaper, or have an option for a mini-version for things like 'tell me more about the cats' and 'i want to befriend the pool monster'.