Feature request: Assign Grab-&-Drag Scrolling to other buttons

[seascape]

Hi there. I found your add-on because it supports grab-&-drag scrolling, and the actual add-on called "Grab & Drag" is broken by e10s, no longer maintained. It looks like Mouse Gestures Suite will also be able to replace my using the FireGestures extension.

So far I only see one problem: I very much prefer to grab-&-drag scroll with the right mouse button, and make mouse gestures with the middle. It's good that you allow the gestures button to be reassigned, but it seems that your scrolling features can only be assigned to middle mouse.

Please let users reassign scrolling functions to other buttons, too, like "Grab & Drag" allowed.

Thank you for your time.