Seriously though, giving Tager double jump would not break him. In fact, it'd probably work out better than trying to give him more gimmicky special moves which don't actually help him in the matchups he struggles with. They don't even need to give his air normals jump cancel or anything, just give him the privilege of being able to alter his course and avoid anti-airs without necessarily committing to an easily punished normal.
RETSUPUREI