Actually, now that I think about it, this glitch might not be faster in 100% since you neon jump to the left wall before calling Zero and are subsequently nowhere near a green charge upon Mosquitus' room, which allows you to bait Mosquitus much further to the right while waiting for your charge.
Here's some
disassembly of the Mosquitus descent behavior that FractalFusion did, since it may be useful for the 100% run Glitchman is working on.
The way it works is, every 4 frames, Mosquitus will poll 3 RNG values. Presumably, 2 of them are for the smoke cloud he creates from being damaged, and one is to determine his direction. Depending on when you kill Mosquitus relative to the global timer, these two events may or may not coincide on the same frames. If they do, the values relevant to his choice of direction are the current value the frame after 4 values are polled, and if they don't, the current value the frame after 2 values are polled. Since the RNG also increments once every frame, this means 7 values will be polled every 4 frames.
As such, this text document has the RNG sequence divided up into 7 columns, so any Mosquitus descent pattern would start on a given value then go down that column for around 30 values(depending on how optimal the pattern is). RNG values with nothing next to them cause Mosquitus to fly towards Zero, and values with letters next to them represent one of eight 45° angles.
This table doesn't account for whether or not Mosquitus will attempt to grab Zero at the very start of the fight, which also needs to happen, so some of these patterns that look good may not be viable. But since you dump the second preliminary buster shot off screen while falling back to the ground, you can potentially drag it off screen quicker or slower to advance RNG at a slightly different rate in between the getting grabbed and the descent(or delay your saber slash).