Two properties - which should be my PPR?

Similar info here although I have missed this two-year window....I guess I will just have to take my chances and see what happens down the line but spend more than 50% of my time in Dublin perhaps.

2.2 How Many Residences Can I Have?
Only one property can qualify as your principal private residence and if you have more than one you have to notify the Revenue which one is your principal private residence for Capital Gains Tax purposes. This notification must be made within two years of the beginning of the period of acquisition of the second residence. Assuming the facts of your circumstances support the property nominated by you no difficulties will arise. If the facts do not support your case you may have to negotiate the matter with the Revenue to reach agreement.

A common situation these days is where one spouse works in Dublin Monday to Friday and lives in an apartment they own in Dublin. The family live down the country in a house owned by them. Which property is the principal private residence? More likely than not the house down the country. However an argument could perhaps be made that the apartment is the principal private residence but might be difficult to sustain.

Couples are getting married later in life these days and quite often each of the couple will already own a private residence prior to marriage. As a married couple they are only entitled to have one principal private residence for capital gains tax purposes. Let’s assume that they live in one of the properties and let out the other one for a few years and then decide to sell one of the properties. If they sell the property that was let at a gain then part of the gain will be taxable. However if they sell the property that they lived in this should be exempt from tax as it was always used as a principal private residence. They could then move into the property that was let and continue to use it as their private residence. On any subsequent sale of this property full Principal Private Residence relief will not be allowed as it was not always used as a private residence.

 
On balance, given that I have missed the two-year notification window anyway, I think it is best to leave things as they are.

Although I think it might be useful to switch my revenue correspondence to my Dublin address.

And we might have another property crash by the time I decide to sell so none of these problems may arise!