Great explanation, IP, thanks. On my last bump I was with someone who did not mind giving me his TCV, but calling reservations I learned that these now need to be used by the person on the voucher. I later asked at the airport and got the same answer. They told me the rules had changed (about a year ago). Is this still the case?
It also helps to have backup plans (on NW) ready when going for a bump. Saves a lot of going back and forth at the gate when one needs to find out alternative routes/dates.