How could Dair even possibly work?
If it requires to hit and land within the first frame then possibly through platforms, or maybe from the ledge. It would be nice if we could do something like this with Nair especially. Nair needs a tech like this way more than Dair does, not to mention, it'd be easier to use.
Edit: I finally got a chance to do a bit of testing on a few things and I have some interesting stuff to report.
I looked into the Bowling Ball clank with up B and I found out that it's not about the first hit, it's actually about the part of the shell that gets hit, The priority is stronger towards the sides that it is directly in the middle. This also seems to be most effective against projectiles, I tried testing to see if it was possible even with the first hit to clank through non-projectiles, we tested with Toon Link's Dair. There was no dice there, but it did seem very effective against Megaman's Dair, and it SEEMED to let me clank with more of the shell even. It clanked the Dair pretty well on the ground too, and with pretty much most of the shell, the only time I got hit was really late into the animation or once when I got clipped on the very very side of the attack while it was grounded. In the air, it just klanked through and hit Megaman. Admitedly my tests on this weren't too extensive, but I think there's enough here for the general concept.
What we spent most of the time testing were ways for Bowser to abuse ledgesnap vulnerability. It turns out that Bowser's Downsmash hits the edge a little better depending on how you're standing in relation on the edge. For instance, if you have Game and watch hang from the ledge and just roll back into the ledge and do a Down smash, you'll just see the last hit knock him off. Now, if you teeter at the edge and down smash, only the last hit will knock him off still, but all of the other hits will glance off of his nose. If you move just a bit back so that about half of Bowser's foot is off the stage then the first hit of the Dsmash will snipe Game and watch off the ledge instead of the last hit. So I tried intercepting ledge snaps with this spacing, and the results look promising. Not only is it capable of catching them snapping properly, or improperly for that matter, but it's quite possible for the weaker hits to position the opponent in such a way that the last hit will cause a stage spike. They will fly directly down if this happens, and with quite powerful knock back as well, depending on the percents. However since this can be a pretty risky way to edgeguard, I also looked into Bowser's Aerial options. These are harder to use, but they can work and fair stage spikes very well.
I've also noticed that the late hit of Fair can hit someone trying to go low in a way that would avoid a normal walk-off Fair or Bair attempt but Reverse Fair will hit them, and will usually send them away from the stage. I think that this might be a pretty solid edgeguard mix-up and it actually gives a use to edge cancel side b since it lets you basically run off the stage backwards, which would be harder to read than turning around and hopping off instead.
I don't have much else to say about the other Aerials, at least not at the moment.
