That's very interesting. I wonder how that would work with the almost universal emotional mechanism whereby all States, Empires, Counties, Municipalities and governments hate losing territory.
I think that, in the case of Norn Iron, it always has been a place apart, part of the UK, but, at the same time, not as much a part as are Scotland and Wales. The UK established it a century ago as a stopgap measure to stop the ongoing murder and mayhem between IRA volunteers and British security forces. It was vaguely intended eventually to unite the two parliaments in Stormont and Dublin. However, the newly-formed Irish Free State promptly collapsed into a bitter civil war (which killed more Irishmen that the British had), whereas the Unionists of Norn Iron, finding they had inherited a population that was one-third Catholic, set out to ensure that these people never got into a position of power. Having created the statelet, Westminster promptly adopted a sort of "ignore it and maybe it'll go away" attitude, letting the Unionists bend every rule in the book to remain in power, and simply not looking at it, until forced to by the events of 1969. It was then Home Secretary Reginald Maudling who, on the plane back was heard to say, "For God's sake bring me a large Scotch! What a bloody awful country!"
My feeling is that Norn Iron is just too different, has too much difficult and (to mainlanders) incomprehensible history and antagonisms, that getting rid of it would be welcome to most mainlanders. (The incomprehension cuts both ways - in the past, Catholic families going on holiday to England would be baffled going to Mass and hearing prayers for the Royal family!)
P.S. Just remembered. Alan Whicker, famous for travels to strange, exotic places, decided to travel to this strange, exotic place on the far side of the Irish Sea, with the intention of making a series of programmes. The first one lifted the lid on what this bizarre other bit of the UK was really like. The governing Unionist Party was furious, and the BBC was forced into a grovelling apology, and to promise that any future programming from Northern Ireland would first obtain their approval. The remaining Whicker programmes were canned, much to Whicker's annoyance.