John:
I have been using the Level Dimensioning Tool for placing elevation markers in plan that are associated with the slab for that level, even for 1 step (6") changes. This ensures that the marker reads the correct height if the slab level changes, in keeping with the BIM philosophy. I agree that the marker you show is ambiguous (when I used this in my pre CAD days I would have put the hatching on the other side of the stepped line). I have not had a problem with the Level Dimensioning markers being misread in the field, but I know local practices may differ. Hope this helps.
David