V16 Build 1605 was released today and in the release notes I see.
Technology Authoring
Shape scripted labels will now be loaded and drawn correctly for extended elements in a profile
So I down loaded the 64-bit version and tried it out. It indeed does what it says on the label - pun intended. The duplication of labels on for shape scripted elements is no longer a problem.
Will do a bit more testing to confirm its ready for release in my organisation.
Huston, I think we are ready for launch.