i can’t imagine anyone attempting to use it but it’s interesting to consider circumstances where it might come up.
eg, what would happen if Harry died unexpectedly like his own mother? What if Harry and Meghan both died tragically in a car crash? Would Charles (or in years to come William) fight the Raglands and the Markles for the Royal offspring?
If so, would it be easier to get custody of Archie (born in the UK) than Lilibet (born in the US)?
(My info on this next bit might be outdated -my first husband was from the US so we did the visa/immigration process but it was 25 years ago).
The US doesn’t really like dual citizenship but tolerates it for those born in the US who then gain the second citizenship on top.
For people incoming to the US, born elsewhere, you are expected to renounce your birth state as part of your US naturalisation. This means it’s potentially much easier for Lilibet to hold dual US/UK nationality than it is for Archie and it’s even more difficult for Harry who would presumably have to give up his entire royal status and all titles along with his British passport?
obviously I do not want Harry and Meghan to die prematurely (!) but the legal situation is a curious situation to think about.
I reckon a divorce would also be affected by the differences in nationality and it would be much easier for a UK based Harry to have shared custody of Archie than of Lilibet.
I can imagine a situation like that (Lilibet’s post divorce country of residence) might provoke a monarch to attempt to intervene on behalf of Harry (or it it might’ve done, Harry’s probably burned that bridge now!)