I already bought BetterTouchTool to enable tap. But I noticed that I have to lift my finger a bit too high because of the already raised surface of the mouse (since it's not a flat touchpad), and also sometimes clicking works better in some situations.Maybe try enabling tap to click in system preferences so you do not need to press down at all?
Is enabling tap in system preferences possible even without BetterTouchTool? I don't see it in system preferences.