As Bduke explained, AIB and EBS have the same policy in this regard.
A borrower whose LTV reduces does not get a lower rate. They get the rate of their original LTV.
Ulster Bank is the only bank which allows borrowers who reduce their LTV to avail of the lower LTV band rate.
There is a small anomaly but I don't think it's relevant to you Tosh. AIB customers on SVR, as distinct from LTV rates, can move to the current LTV rate. EBS customers stay on the SVR rate. I have been told that by AIB guys, but could not find it written down anywhere.