I found interesting how you combined those effects.

Too bad I don't like god characters.
For your question, you can't do that because tilts/smashes actions are coded to send you to air state whenever you leave the ground while performing them.
In my koopa psa, I made a workaround during the attackHi4 subaction to make the character leave the ground, you can see there to make things easier. It basically uses a variable and change the action during an attack that occurs randomly, with this action being one of the special attacks actions, but it is only read when the action is triggered during the up smash. In this action, you can code your own physics if you have to.
It works, but perhaps you can do that with action overrides nowadays, I didn't have this option back then. But I don't know how they work, so far I never needed them.