Input detection in between Updates - rhythm game

Is there any way to get input updates faster than Update frequency? I would like to be able to react to input much faster than 16ms (say 2-4ms) without increasing the framerate - I would like to do it also on Android which is framerate locked.

I found on the forums that it was considered, but it seems that it was left unfinished:

I want to update some things that are not on the Unity’s Main thread - audio and other hardware. So if I only get input with timestamps at the beginning of the next frame it’s too late, can’t interpolate it like e.g. position.

The next question would be if I can somehow make audioSource Play/PlayScheduled from secondary thread.