FWIW:
20-09-2018 I send transfer papers to UK CAA + Irish IAA.
02-10-2018 IAA charges EUR 250 to credit card.
09-10-2018 CAA charges GBP 45 to credit card.
23-10-2018 CAA contacts me via email because they want to take another payment, but have already destroyed the form with my card details. They say I should have sent two copies of that form, one for licensing and one for medical! I pointed out that it's one application, and that if it involves multiple departments they should share info before destroying forms... they wouldn't listen. Gave them card details over the phone, new payment of GBP 77 taken same day.
27-11-2018 IAA contacts me via email saying they received medical info from UK. However CAA had written that I took an ECG in 2009, but did not have any ECG records attached. IAA asks me to contact my doctor to forward ECG records. I replied that I never took an ECG (why would I, not required for Class 2 holders under the age of 40) so this is a CAA mistake. IAA employee forwards this to medical assessor.
04-01-2019 I write an email to follow up on progress. Reply from IAA same day, ECG discrepancy resolved and licence almost ready.
10-01-2019 Irish licence ready, can be exchanged with old licence either in person or also via DHL without going to Dublin.
Thank goodness for Irish common sense, I really thought that ECG thing would stall the whole process! I'm sure if it was the other way around the CAA would have demanded authenticated proof of the exam never having taken place.