With reference to cabin crew bidding BASSA have always denied BA crew this. When the 767/Midfleet operated they went all out to rubbish it even though, for the most part, it worked well.
Before anyone pops up and disputes this the flaw was the Purser rank: Shorthaul 767- 1 Purser. Longhaul 767- 3 Pursers the Purser rank on Midfleet had a preference for SH and therefore didn't achieve satisfaction.
BASSA reps are true Luddites any thing new is to be opposed at any cost even if it is beneficial to crew.