I think I would just let it roll and see what happens. Throw popcorn if it seems like someone is trying to grub for trigger, but if a person is really hitting that thing like 5 times in a scene, score!

After a couple of sessions, you’ll see how many advances each player has and you can all think about whether a house rule/clarification is necessary. But after re-reading Chap 7, I think the best bet is to not to try to fix it until your sure it is a problem.