“Unless they are not domiciled in some part of the United Kimgdom…”
Harry would be DQ.
I think it would have been allowed if he still had Frogmore cottage but he has got no home there now. However, a lot of rumors going around that he wants to establish a home there.
Say for example that he divorces Markle. I don’t see that marriage lasting. He comes back to England.
No way should he EVER be allowed to be Regent but Parliament might soften towards him if he came back without Markle.
And like Markle purportedly said, one plane crash away from King Harry...even after you get King George if he dies with no children and charlotte has no children and louis had no children. that is why they need to not all travel together.