You can run a second wire for untagged traffic. I started a post about this issue a couple of months ago.
Just cross your fingers this becomes possible in the next firmware version.
As a workaround, you can try to put everything on a VLan (nothing untagged). There are PNP limitations to doing this depending on the application doing the PNP requesting.
Another option is to run a second wire - one for untagged traffic, and one for tagged.