I've used the QF bid upgrade on a couple of LHR-DXB-LHR sectors upgrading from Premium to Business. These have been confirmed in U inventory and while not being eligible for chauffeur service (this has to be booked at least 24hrs prior on chauffeur eligible routes and ticket types, bid upgrades confirm less than 24hrs before) they attracted business tier points (same as I/R class fare level so 140 ew) and the corresponding amount of avios. BAEC number in the booking throughout so no need to remove and re-enter. The only thing I will say is that bid upgrade uses an unknown algorithm (at least to me!) and you can't count on them showing up in a similar way that you might see a POUG offer to upgrade on a BA journey.