When editing points on a curve SOP the GUI has a different handle compared to the usual editing GUI. As a result it doesn't seem to be affected by my prefs. Is this per design? Wouldn't it make more sense to just get the bring the edit sop capabilities into the Curve SOP? The same thing could be said about the Add SOP.

The underlying handles should share a lot of the code, so should be subject to the same preferences. Which preferences aren't affecting these handles?

Well, for one the m button doesn't seem to do anything to the handle. And I don't seem to affect the handles when changing the MMB indirect mapping pref. Maybe it's a lack of visual feedback, I generally don't know if anything have any effect when changing the prefs.

The underlying handles should share a lot of the code

That's good news. Is it a big ask then to move multiple points at the same time? Ideally moving the whole edit GUI into the Curve and Add nodes?