How to make scrolling shortcut faster?

I’ve set a shortcut that changes the volume when I press the side button + scroll wheel on a non apple mouse. The issue is there is a significant delay. If I scroll multiple ticks in a row, it only changes the volume by one step. Is there a way to remove the delay?

I'm not quite sue (can't test right now), but I think this setting should apply to button +scroll wheel:

Thank you, this was what I was looking for. But I also noticed that this shortcut doesn’t work in full screen. Does that have anything to do with BTT?