>>51725921All the gimmicks would need rework, some more than others, but I think it's possible if done right.
There's already checks in place to prevent a Pokémon from using more than one gimmick, like having the Pokémon hold an item to activate; Dynamax doesn't have that restriction, but I think it needs that nerf.
Terastal I'm not 100% sure on, but ultimately I'd say it shouldn't overlap with the others. Some Mega Evolutions somewhat rely on changing types and who knows how crazy the damage would be if you had a Tera Normal Snorlax use Pulverizing Pancake.