I was practicing in training mode as Falcon today and my opponent and I were both below the stage. I knew if I spiked him, I'd die, so I up-b'd and he fell into the footstool animation. I ended up edgeguarding him. I did a little more looking into it and it turns out that if you have tap-jump on , you haven't used your second jump, and you time it just right, you can footstool into an up-b.
I don't know how useful this could be, but I think it's pretty interesting.
I don't know how useful this could be, but I think it's pretty interesting.