Let's clarify so I don't get an infraction for being "mean." You all only get one..........
IATele is around 27-30 start up on perfect input dependent on the follow up button pressed. If you can't react to that in the neutral with an ambiguous s1, NJP or d2 then FGs are not for you. That's right around half a second...
Used properly Impostor's iATele is a reaction tool, not really something to start an offense from fullscreen. If the opponent is slow and/or an idiot and can't react to the tele then yeah, it's going to become an offensive tool. Every character can deal with tele, some easier than others. Varying jump height is the only "mixup" in regards to what you may or may not get the chance to use with your character as a means to AA Shinnok out of the tele using the appropriate tools.
There are seriously much worse things to bitch about in this game than Impostor's tele of all things. Lab more, bitch less. Or... Ask questions. Wrap your head around that.
I know it's hard for some.