Thanks both, that’s smooth!
I do think it would be nice if it was part of Rhino and I wondered if it already was, as a hidden command like join has ‘crv’ to force joining a curve from other inputs like surface edges.
Btw I use this script on a button now when I want to move something constrained:
import rhinoscriptsyntax as rs
objects = rs.GetObjects("Select objects to move",group=True,preselect=True, select=True)
osnap = rs.ProjectOsnaps()
if not osnap:
But it forces me to choose the tool in advance (which is OK of course) but I think the workflow would be even smoother if I could just hit M and then C to force it. (P would make more sence, but is further from M and the Spacebar than C is )