Sounds like you have no case.
You are on an amazing tracker margin and AIB made right the interest overcharge between 2008 and 2011.
Thinking about it, the value of your tracker is phenomenal, if you got an interest refund of €11k for less than 3 years, that might include some compensation maybe but effectively, you are less than a third of the SVR for the next 8 years, less than half of the current best AIB rate, that is so valuable. I would expect there is a less than zero chance of the FSPO finding further in your favour.
The prevailing rate cohort has entirely different circumstances. Even if a tracker was awarded to us, which by and large wasn't, the best margin rate expected was 1.5%. Count your blessings.