I agree with you @Pat L'Heureux. It’s very time consuming when dealing with for example revisions and you have to manually change the rim height of all manholes. And doing it the manual way makes a big risk of you missing one manhole or two when updating. Great idea of tying the structures to a surface.
In Trimble novapoint you associate utilities like this. You tell the software which surface to tie the trench to( like TBC) and what surface you want the structures to tie to.