New 'kingdom' is now needed
Now that Ian Paisley is laid to rest there are many in Ireland and Scotland who would like to see the old Protestant United Kingdom along with the old Catholic Republic laid to rest with him.
Ian was a vociferous champion of the old Protestant UK (threatened by republican violence). Ian saw the old UK as a Protestant Kingdom for Protestants. James Craig saw the Kingdom the same way. Both men were constitutionally correct.
The Coronation Oath makes clear the duty of the monarch is to maintain the reformed faith. So sectarianism is endemic and makes it a cold house for Catholics. The Oath needs to be changed from the "reformed faith" to the "Christian faith".
A replacement Kingdom is needed – a Confederal Kingdom where a confederation is a treaty or pact between constituent sovereign nation states dealing with such things as common defence, common trade, a common policy towards the EU and the UN or fair treatment for minorities.