I was messing with the launch speed code and managed to get rid of Shiek's f-tilt lock.
I used 00320064 for both bubbles.
What this does, instead, is that it hits the opponent into the air, high enough and long enough for an uair or bair depending on their DI.
This, however, prevents the overpowering of Luigi's kick, Falco's tilt and upsmash, and anything else sharing this bubble.
Could others test this?
Edit: BTW, luigi's nair kills mario at 137, and falco's upsmash kills at 141. These are considering the damage AFTER the hit, not before.