If they have JAR-FCL licences, they change the State of Issue to somewhere which has an NAA more sensible than the UK CAA, such as the Republic of Ireland, which does recognise the validity of ICAO IRs.
Are you saying that if you have a JAA IR which is outside its revalidation (so it needs a renewal) but you are current on another ICAO IR, you can change to Irish residence and recover the JAA IR?
What would be the procedure for that?
Surely you need to live in Ireland, or something like that, because under the new rules the State issuing the license needs to also hold your medical records.