Thanks, I eventually discovered it after a ton of trial and error. It's a shame though because the whole point of a touchpad is multitouch gestures which actually make navigating CAD applications pretty nice. I'll use a touchpad or a combination of touchpad and mouse in other apps like KiCad and it works quite well. Seems to me like all these open source programs should be stealing/sharing the best implementations of some of these basic things like 2D/3D input controls with each other.