There's been debate over whether using analog left or digital left is better for 1 slash, and there are cases for both.
Using analog left increases your max fallspeed, meaning the window to clear the ledge is tighter, but if you do clip the ledge, since you'll continue walking right you can sometimes keep the WCS anyway.
Using digital left increases this window, but I've also noticed it tends to turn you to the left when you enter the water if you continue holding it, which can also eat your jump for some reason, so you either have to eat this timeloss or stop holding the WCS before entering the water.
Switching between digital and analog, as shown in the clip, should give you the best of both worlds. You get some reduced fallspeed on the first dash by holding digital left, then switch to analog in case you clip the ledge and so you don't turn when entering the water.
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