UPDATE: After the Office repair (which failed at the end, with some
"Bootstrapping" error), I found the OneNote port. Maybe it was there all
along and I missed it, or maybe the repair brought it back.

After some more fiddling, I got it to work again. Had to make sure the port,
driver, and processor were all set to OneNote. Still chose a "dummy" printer
in the first place.

All good and well, for a minute or two, but now it stopped working again,
"Microsoft XPS Document Printer" has stolen primary printer status, and in
the "Printers" control panel my new OneNote printer is listed as "Deleting".
Why!!!!