[mizaru]

>if you press fast (within 200ms) you don't get a UI but the switch will happen

I always get the UI, no matter how fast I press the keys (W10 1903). This may have been different on previous versions.

[userbinator]

XP and 98SE (I just started a VM to check) also don't have any delay, so I suspect that those who are seeing one are just experiencing some natural sluggishness rather than a deliberate delay.

[lwouis]

Indeed I tried and even though I can get a switch without any frame of UI showing, it is very hard to press and release fast enough. It's not a delay like I implemented, but most likely the UI being terminated before the next frame, so nothing shows.

In any case, adding a preference to change/remove the delay will satisfy people who want the UI to show faster (https://github.com/lwouis/alt-tab-macos/issues/8)