1, as long as you know the name of the fill, no need to define it. But the default name is localized.
2, I agree, it would be nice. But you would still have to do extra work in GDL to use them.
3, I didn’t try if a rotational and a moveable hotspot can be linked like two moveable hotspots can.
You could also try using a moveable hotspot for the origin, one moveable for the end of the radius, and doing the computations in the background with linked hidden parameters, showing angle/r instead of x/y in the tracker.
Library Platform, Software Engineer