Hello,
After several searches, it seems we still cannot lock mouse scroll zoom direction in Grasshopper to be sync with Rhino, unless by using a ZoomScale = -1.1 (RH-36624 & RH-36648).
Unfortunately, this ZoomScale of -1.1 is acting weird when using trackpad zoom gesture.
But, can we imagine a script / macro detecting when the mouse is physically connected and, if so use a ZoomScale = -1.1, if not ZoomScale = 0.9 ?