But you have the problem of 5-10% of the population that is viscerally opposed to this. That would still be a huge problem with no easy solution. N
You could relocate the Ulster loyalists to Appalachia, they'd feel right at home.
Realistic the Irish should become a monarchy commonwealth like canada to appeal to the loyalist if they are actually seriously about wanting to have a true ireland for unionist and nationalist not like the president have power or anything. they wont because they wont give two sh*t about the loyalists once they are united.