Back from work. Was able to test the Ganondorf Aerial L-canceling. I can confirm it works for every aerial attack except Fair.
Nair and Dair require you to double jump.
Uair and Bair can be L-canceled with one short jump instead of needing 2 jumps.
These attacks can be canceled into all his specials and standard attacks but the timing for Down special is super strict and I imagine the same applies for his down tilt. That said I can consistently cancel into his jab, kick, axe kick, side smash, up smash, Up B, Flame Choke, and Warlock Punch with ease.
This could be really useful especially with Flame Choke.
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As for that Bowser tech I think I know the trick now, but it is situational. According to Xadrin off of Gamefaqs:
"It works the same as it did in Brawl. Bowser's up B has certain frames where you can land without any lag. You just have to use up B when Bowser is at a certain height to make it so that he lands on those frames.
Keep using up B off the stage when Bowser is at the same height as the ledge, and you eventually will see it."