The situation is that the IAA do allow it as do the CAA with some important differences. The IAA will add the rating with a restriction which is that you can only fly UAE registered aircraft. This effectively keeps your licence & IR alive. Every time you do a sim in EK you just forward the paperwork by email to the IAA and they will revalidate it. There is an initial fee but it's free after that.
You can put your rating on your CAA licence but you will need to do an LPC every 12 months in order to keep it valid. It has to be a separate LPC conducted by a UK CAA examiner. For some reason the UK has not adopted the restriction that Ireland have, under EASA.
Not sure what the cheapest option for you will be - depends how long you intend to hang around!