The Good Friday deal doesn't entitle everyone born in NI to Irish Citizenship. (anymore). It's a little more complicated than that for people born in the last 20 years.

> Since 1 January 2005, if you are born in Northern Ireland, you can claim Irish citizenship if your parent (or parents) are either British or Irish citizens, or one of them has lived on the island of Ireland for at least 3 out of the 4 years immediately before your birth.

> unlike Northern Ireland, and maybe Kent, does not have a land border with the EU.

NI's Land Border with Ireland is a "special" border. Ireland isn't in the Schengen Area (IIRC Cyprus is the only other EU country that isn't Schengen), and as a result of that has passport checks at all arrival areas - this is _because_ of the border with NI already. It was already special cased, and thankfully hasn't ended up with a UN buffer zone as a result of this mess.

That said, I agree with you 98%!