Heres what i've come to find about the ledgedash:
its really hard to airdodge too early. Like, he has a 1 frame second jump ffs, and it takes a few fractions of a second to clear the edge and be onstage. Most people think of ledgedashing as being super risky for suiciding, but its actually pretty hard to suicide once you get used to it.
the hardest part (for me) is falling from the ledge quickly to preserve as much invicibility as possible, and then jumping. Hence, my most frequent problem with the ledgedash is jumping too early (while im in my ledgegrab animation still) and getting that terrible standard ledge jump, which isnt as bad as straight up sd'ing.
This is my opinion and how i got much better at it. Once i understood that its actually pretty hard to airdodge "too fast", then i got way better. hopefully this makes sense?
Also, lets talk about ledgehop bair -> regrab (without landing or upbing). its so freaking baller and covers so many options.