The problem with logging it as "Case A" is that you will invariably get into a situation where both yourself and the instructor will want to log P1 which clearly is outside of the rules considering you are in a light aircraft that is not certified for multi crew operations/no AOC etc etc. Therefore H seems to be the only thing left until the CAA come along with a new letter. I is free!
As for P/UT I was always taught (and that table seems to bear it out) you log this when under recognised training. In a checkout where you are acting as the commander and demonstrating your skills mainly for insurance purposes I can't see how this would fit under P/UT.
I agree it would be nice for the CAA to add to their notes and assign a letter for these sorts of things as it is a regular debate. That way we can put it to bed once and for all.