>>36442933I made a Magic Room team several years ago which made use of boosting mons with choice items, since choice items can effectively take you to +10 if you max out, or +4 if you get to +2, etc. Scarf Uxie -> Magic Room -> Filler Turn -> Filler Turn -> Memento -> CB Scizor (for example) -> Swords Dance -> Swords Dance (Magic Room wears off) -> Bullet Punch is pretty devastating, but hardly ever works, and you need to have the turns work out precisely or it falls apart. It's not useful in any other context that I'm aware of, since it deprives both players equally.
I've also tried running Wonder Room Nihilego recently, and it's just never really worth the moveslot. In order for it to do much of anything, you need to fully invest in SpD, but even then it's still less powerful for increasing defenses/offenses than a regular boosting move.
These moves just aren't viable, and I don't think anything will fix them, especially since making Trick Room mutable would also probably involve making the other Room moves mutable.
Consider that, for Magic Room, I can only find a way to make it work by controlling when it wears off, and the latter needs to be controlled by the user as well in order to manage which defense gets hit. Making the user have less control of them by making them work like weathers makes them even worse.
