I’ve been looking over the PDF and I have a question; I saw that stats are capped at +3, but does that cap apply to bonuses too? I can’t find anything about that and I worry that piling pluses will kind of break the system.
If you are talking about piling on plus ones from the We can do it move, a person helps and then the person they are helping should take the action they are being assisted with.
There are rare occasions where things can be constructed in a way to allow many +1s to happen at once, and I've seen it happen once for one roll.
In things like combat, I will usually allow 1 person to help, but I've talked to other GMs are fine with letting multiple people help. The thing to keep in mind is the narrative and that the world won't wait. So as each person tries to help, the world should be acting alongside those actions.