limiting rotation in pushbutton QD sling cups

[strongpoint]

anyone know a way to accomplish this? could it potentially be as simple as displacing some metal into the track in which the ball bearings ride? i know there are plenty of externally mounted sling cups that feature limited rotation, but i'm interested in modifying a set of flush cups that don't have this feature.

i'm turning over some sling mounting ideas in my head, and this is one of the last obstacles standing in the way of one solution.

[swifty]

Drill a hole and put a pin in the cup. Drill a slightly larger hole in the swivel part that matches.