If it helps, I find that when you have players who got a transform for the stat card, it helps to treat them like that isn’t the case, even if you know it is. If someone became a Death Elemental for the L337 skillz, but they are constantly approached by NPCs who call their bluff and expect them to actually act like a Death Elemental, they will either shape up and adapt to the RP, or ditch their transform.

One way of handling the power disparity between transformed and not-transformed PC is to only activate transforms on closed mods. So for a weekend plotline that involves a bunch of different modules to solve, one of those might require that PCs be transformed to go. Sometimes they make weird exceptions and give non-transformed people temporary empowerments if some IG circumstance requires them to go on the mod, but otherwise its pretty strict. So having a transform gives you the ability to go on these ‘pop mods,’ but it’s never activated in mixed company.
(I’d never heard of this way of dealing with them until I played in Massachusetts, so it definitely seems like a Northeast thing, but it seems like something that could easily be applied elsewhere).