Booked in WT+ earlier in the year from LHR to ORD. Got my BP for WT+ at Edinburgh. I didn't have luggage so no bags to check in so no one saw me until the gate where the machine spat out my card and the agent wrote my new NCW seat number on it.
BTW - I have done SFO to LHR in WT+ a few times and found it possible to survive the 11 hours in the single seat (28 BorJ I think), a several bottles of wine, and a sleeping pill.