I recently learned about the holding down the analog tech to do the down up kind of teleport and I was wondering If there was a similar tech or anything that could help me do shirai ryu s instant air teleport
This. Takeda is well known for being more of a "not-so-execution-heavy"-character for beginners. It is actually pretty easy to do! Just keep on trying and you are gonna be able to pull it off in no time!
So I think to answer your question??, you can do it once you leave the ground if you're fast enough. Like however fast you can do Kitana's IA fans is how fast you can do the teleport.