This speedtech lets you do the somersault you usally do on shortcuts everywhere and chain them together as well, being able to reach ridiculous speeds if done correctly. Was found by @ElCidDK on Twitter: https://www.speedrun.com/user/ElCid

You get a certain amount of speed Jump let go of forward after jumping press forward again shortly before landing and hold it jump let go of forward after jumping and so on. here's a gif showing the inputs https://imgur.com/ufDJ1Rh