This is the faster true ending shade skip setup not counting the 0fb version coz fuck that noise. Align yourself with the left side of the door and do the three full jumps as normal. The more diagonal you can move with your shade the faster.
Also attached in the second clip is the same setup but done with 1 fireball. You have to move a bit more vertically and make sure the pogo after the parry is at absolute max range. Kind of a meme but if you get a promising dboost and pogo you can do this one on reaction to that.
Both of these clips were done at around 350fps as per the counter in the top left, and should be easier at lower framerates. I can't get 600 fps in that room but if you do the 1fb version may be quite difficult if not outright impossible.
As per TE shade skip general guidelines, if the shade fireballs mid skip you're just going to have to play by feel but starting it further left like this gives you a lot more space to work with to try and save it so it should be slightly preferable to if you were going for a further right setup.