Interesting views on a subject that gets aired every six months or so. Last time I saw this discussed a difference between multi-crew and single crew aircraft was pointed out.
(Unfortunately the CAA website is down so I can't quote the relevent GID verbatim).
I seem to remember that the consensus then was that P1u/s could only be used by single-crew aircraft pilots when logging a successful flight test. There were many instances where logging P1u/s as a multi-crew member was appropriate.