4.212 unreliable handling Smart Mouse regions

I want this to do -one thing-, extend the left mouse click region on a Magic Mouse to a bit to the right of the middle of the mouse. I have one configuration setting. So nothing fancy.

The latest version I have, 4.212, is very unreliable in this regard. Sometimes even on the left side of the mouse I get 'right click' events. Other times I get no events. It -seems- these errors are more likely when it's been a while since I touched the mouse, but I have not tried to measure that in any way.

Is anyone else seeing this?

If this mostly affected double-clicks, it might already be fixed in the latest alpha version!