Hi aiden, I was on a 13a probationary when I left last May (1 day before expiry - BoI thought I was crazy as I'd have to start again but there was no path to downgrade back to Tourist) ACR-i just expired (i did have the Annual Report OR but wasnt looked at), had to pay about P2000 to leave paying at a seperate window in NAIA plus the terminal fee. My circumstances changed dramatically else I obviously wouldnt have gone through the pain and cost of applying in the first place. I had no issues once back, registered with the Docs, started work with my old NI number, tax and NI deducted as normal. Only thing i did get was a letter from the DHSS saying I hadnt contributed enough contributions in the tax year so this would effect pension payments in the future.
I went back to the RP for Christmas and just entered and left as a tourist, no issues or questions. HTH