I find that dimensions snapped to blocks in 3d space have a history of unreliability in Rhino which doesn’t exist with 2d geometry.
Mcneels’s recognition of this issue isn’t reliable either, with techs agreeing there’s an issue and planning to investigate without follow up and months later questioning whether there’s an issue at all.
See Lowell’s initial response vs Pascal’s response 8 month’s later:
And the absence of follow-up here:
I don’t think it’s a priority at McNeel.
Without reliable dimensions in 3d space, using it for construction drawings is impossible.
My opinion is that McNeel’s orientation is to reinforce it for the creation of nurbs models to be exported into construction drawings in other CAD packages, which makes annotation issues like dimensioning a low priority.