If you hold a UK issued EASA ATPL, then you are exempt from the seven-year time window, providing a valid IR rating has been held within the past seven years in a non-EASA licence. As far as I am aware, the UK is the only country to seek this exemption and it apparently was driven by British expat pilots in Cathay and Dragonair. I migrated from a UK issued EASA ATPL, to an IAA issued licence a couple of years ago. The IAA confirmed last year in writing to me, that the seven year window does apply but a restricted (A6 only) rating will restart the clock for another seven years.
On a personal note, I can confirm that the IAA are a joy to deal with and correspondence is replied to normally within 24 hours. I have always found them to be very helpful and friendly.
The letter below from the UK CAA in 2013, might be helpful to clarify the above.
