WI: George III accepts Catholic emancipation?

George III's greatest ally and longest-serving PM, Pitt the Younger, was deeply devoted the United Kingdom project and pushed hard for concessions to be made to Catholics, understanding that a Protestant minority could not rule a Catholic majority in Ireland forever and that Catholic emancipation was necessary for the United Kingdom to succeed. George III rejected this, believing it would be a violation of his coronation oath to protect the Anglican Church. But what if the legal scholars of the day had successfully prevailed upon George that this was actually fine? How would Ireland develop in the 19th and 20th centuries? How much more successful would the United Kingdom be? Or would the government still treat the Irish as second class citizens, feeding Irish nationalism and ultimately leading to a situation like the one today?
These threads may be of some help: