Got a reply during the week from BDO with a response from AIB who are adamant they've done nothing wrong and there was no financial loss to me. AIB got my house in 2016 due to it being unaffordable after the death of a co-borrower, but if I had been on the tracker around that period it would have been more than affordable.
I am going to reply to this to ask for proof of their assertion.
I did ring BDO to ask is it worth my while and was told that if there is ANYTHING you want to bring up, that replying is worth a punt rather than regretting not saying something if you feel you should. The bank have 10 days to respond then (after 5 days processing). I then got a letter from BDO the following day to say that when the appeal does go to the board it could take up to 18 weeks.