Obscured feature in rover autopilot waypoint list [UX]

[olanti-p]

I've been using the rover autopilot for a while, and had a usability problem with not being able to clear the list of waypoints in this window:

It's not a big deal when there are a few of them (like in the pic), but becomes very annoying when the number grows.

Today, I've alt+tabbed out of the game, and noticed that for a split second the UI changed:

Apparently these buttons change their function while Alt is pressed.

This seems unnecessarily complex? There is plenty of space for dedicated buttons, and far as I can tell, no other menu in the mod uses such UI mechanic. The only way to discover this feature is either by accident, or to press the "?" button and read explanation for the menu (which I didn't do because the menu appeared self-explanatory).

KSP 1.12.5.3190, MechJeb 2.14.3.0 (latest) installed via CKAN

[olanti-p]

Btw, the "?" button for the main rover autopilot window doesn't seem to be doing anything.