Hi,
As long as it is not a "STAY" type of collision or trigger events, you will be fine with any number of collision events checking in terms of performances,
now... I have a project doing such things, and I have to say I did had some problems, I never found the real sourc e of the problem, but I suspect it is because I use too many collisions check in one state ( I might be wrong tho..) but basically, I started experiencing some corrupted debug flow content, where for a given collision event, playmaker would start loosing its babies and say that a given fsm sent that event, even tho that particular fsm does not even send an event to begin with, so it was clear some pointes issues arised.
so I would really do a FSM per collision detection, I reached 5 6 collision event detection action, and that was ok, but I would not go for more. But Iw as using a lot of tags, weird complex physics set up, mixed colliders, concave convex, etc etc... I ended up splitting my colliders into smaller more discrete and simple volumes to overcome this.
bye,
Jean