U can suppress knit, then dimension and then unsuppress knit, a option if it is a one thin drawing,do not know if it will automatic update drawing if u change part.
Interesting Jason,,, Yes it does seem to be the surfaces that is causing the issue. I'm not sure what they are for but I suspect you have your reasons. I noticed if I hide all the surfaces (shift select) in the part it dimensions ok.
Edit:... I'm using 2016. Do you have these options?
This seems to work.