I think you may be confusing Ireland and Northern Ireland here.
Dublin is not in Northern Ireland (NI), it’s in Ireland... they are 2 separate countries.
Northern Ireland is part of the UK, which means if you were actually to move there (i.e. to Belfast) it would just be like moving from England to Scotland or Wales... you wouldn’t need a new visa as your FLR(M) would be valid there, and you could just qualify for ILR from Northern Ireland.
However, if you are moving to Dublin, that’s in Ireland (which is not part of the UK), so you will need to apply for an Irish spousal visa to move there.
Unfortunately though, if you leave the UK and make Ireland your permanent home, you likely will not able to qualify for ILR in 2024... because to qualify for ILR, you have to prove that:
- the UK is your primary residence and you spend most of your time living there
And
- you and your spouse have lived together for the entire length of the visa
If at all possible I would continue living in the UK until you qualify for ILR and citizenship, and then consider a move to Ireland in 2024/2025 once you have citizenship.
See here for how to qualify for a spousal visa for Ireland:
https://www.citizensinformation.ie/en/government_in_ireland/ireland_and_the_uk/residence_rules_UK_citizens.html#Sent from my iPhone using Tapatalk