Simply disabling the button leads to people thinking something is broken, so you need to add a visual "disabled" state - which should probably be separate from the "you are currently pressing the button" state.

In most cases that is going to lead to annoying pointless flickering as most actions & animations are basically instantaneous, and with touchscreens even in the non-pointless scenarios it won't have the desired effect as the button itself will be hidden from the user by their own finger.

In principle I think you are right, but in practice buffering presses is often probably the more user-friendly option.