I would consult Pass Labs before doing that. Is there a switch somewhere that selects single-ended vs balanced output? If so, maybe. If not, then don't. But do consult them.
I have a question. You wrote, "I am currently trying out a Pass Labs XP-25 phono stage and enjoying what I am hearing, particularly with an MC Step Up Transformer feeding into it vice using the MC settings available." I suspect there is a typo in here somewhere. Tell me you are not running an external SUT into the MC inputs, but if you are, it's surprising if you like the result.