Hi Frank, (achieved in VW 2019)
We do all our annotation in the design layers and copy it over to the viewport annotation. Nevertheless I was intrigued.
So I went to our ground floor of our 3d model and inserted a dimension (1926mm) and converted it to layer plane/3d (not screen plane) in the OIP and manipulated it to the correct plane using Control L (Vertical) You can see it on the right image model view in front of the door.
I then went to a section viewport of the model and the dimension wouldnt appear ....until I checked "display planar objects" and it appeared!
I may have misunderstood your question and we do all our work in 3D, but I hope this might help in some way to get you from A to B
Regards
David