I have a family, this supply register, which is meant to cut the ceiling for 3D presentation purposes, but on RCP I just want to see the symbol for supply or return. See below:

I've added a filled region to cover the cut geometry, which you can see as well as the cut geometry, when I highlight over the family, shown below:

In RCP, it looks exactly as I want it to. However, when I export to PDF as vector, the filled region does not mask. Neither does a masking region. See below:

I also tried as raster, and it does mask in raster, but my line weights are incorrect and obviously the vector is preferred in PDF, see below:

Is this a bug? Is there a way to get this to work? I'd prefer to have this as one family as opposed to two separate families, one for 3D purposes and one for plan purposes.
TIA