Thanks for the explanation man. Would it be correct to say that if you're in hitstun but not in tumble in midair, and then while still in hitstun you stand on the ground, you will also be able to act the frame immediately after you land?Crouching reduces hitlag and knockback by 1/3.
Crouching reduces kb (and therefore hitstun) of any hit regardless of it being set kb or growing kb.
If the move launches the victim into air (i.e it doesn't spike) and it does enough kb, but not too much so that it knocks down, the victim can hard land via ASDI down (which happens naturally when you're holding down for crouch), and all hitstun gets cancelled. So often when you successfully crouch cancel, you'll only have your regular landing lag instead of a considerable period of hitstun, and that is why cc + asdi down is so powerful.
Lasers happen to be so weak that hard landing doesn't occur, which is what SplitsOnTrees meant.
If the jumpsquat of the char is X and you input jump frame 0, then you should input airdodge on frame X.