Update 1500 today
Someone helpful on the gold line went off for a long time, and came back with some 125 ticket numbers, one per pax. These apparently have the Avios and tax paid for UUA embedded in them. With these, I can ring BA ticketing, and book manually. The original price paid is 'held' in them.
So I don't need to use AMEX to rebook - I am beholden to price changes between me seeing the fare on BA.com and ticketing issuing it - but that's OK(ish) and I have the UUA protected (assuming availability on the sector(s) I want)
They said this roundabout shenanigans is indeed SOP - apparently the combo of cash fare booked with a TA, followed by a UUA done with BA, means that standard Corona BWC stuff doesn't apply (????)
They agreed it was indeed slightly odd.
I can't be bothered to fight anymore - but I did say to them - this surely means no-one will UUA at the moment, and that surely no-one should be using a TA if they want Corona protection. She sort of agreed. I asked about the links [MENTION=566057]KARFA[/MENTION] mentioned - she said they didn't apply when UUA had happened (??? again)
What a palaver, but glad it's almost done. Thanks for helpful advice as always on here.