Isabella

Can you airdodge lower to the ground?

Sorry for the late response I don't follow twitter so much. To answer, no, that seems to be as far as we've been able to do.

How applicable will that be in the actual game. It looks almost like when someone in melee is first learning how to wave dash - when they still leave the ground for a few frames.

For Lucario, at least, not very. The height required to do it is pretty large, and it is easily reactable, etc. In melee, this is far from the case. It is fast and hard to react to and as such can be used effectively to space well.

Hmm, is there anywhere I can know the characters that can do this ? Also, does it has much endlag or.... seems usable for competitive play and actual movement ?

As far as I know, no definitive list exists, as this is new. However, I can confidently see that it will not have large applicable usage in competitive play due to it being extremely reactable and not lagless like it was in Melee. If anything, it's just something flashy to do.