I've been asked for these enough times that I'm just putting them here so I can link people.
Fair warning — these are what work for MY hands on MY phone with MY controller. Copying settings straight from a creator is one of the most overrated ideas in gaming. You'll probably want to tweak from here.
Repeat every: 12ms. Faster and I get double-inputs on flicks. Slower and my flip resets feel sluggish.
Delay until repeat: 55ms. This is the biggest one people get wrong. Too low and single taps register as holds; too high and doubles don't come out at all.
Hold down duration: 45ms. Feels 'crisp' — that's not scientific but it's the word I keep using.
Boost is my only exception. I set it to a straight hold with no repeat because I want it to fire the instant I press it and stop the instant I let go. Anything else feels laggy in aerial duels.
Try mine, play three matches, then start adjusting one value at a time. Don't change them all at once — you'll never figure out what actually helped.