So as usual the email I got from BA creates more confusion. My records say that I had an FTV 'bucket' comprising a cash sum against two 125- voucher codes plus a GUF2. However the email I just received from BA says I now have an eVoucher with more cash than I was expecting, under a different 125- voucher code, with no mention of the GUF2.

And if I can't use the cash component for taxes and fees for an Avios booking, can I at least separately apply the GUF2 to an Avios booking? And if I subsequently have to cancel that Avios booking, would I lose the GUF2?

The email almost laughably says 'there's no need to call us' but that's exactly what I'm going to have to do to try and figure out what the hell is going on...