Honestly, I hate to be That Person, but the only way they are going to keep people from taking their masks off is to evict them from the park. If they can see people on rides through cameras or whatever, those people need to be stopped as they disembark. Their ticket gets scanned and they get one "educational contact" about Disney's mask rules. If they get caught again and their ticket is scanned a second time, then they are escorted out. No exceptions, no excuses. Otherwise, this is going to snowball fast and hard.