Philip had his fair share of completely out of touch gaffes, but even he wasn’t so stupid as to believe it wouldn’t ruin everything for him to exercise their “power”.
Just because he’s selfish and doesn’t want to jeopardize the things his position brings him, doesn’t me he bears no responsibility or culpability.
Maybe refusing royal assent wouldn’t change anything (it likely wouldn’t), he still assents and the law goes forward with his name on it.
There's case law on this matter actually, coming from the trial of King Charles I.
> The court challenged the doctrine of sovereign immunity and proposed that "the King of England was not a person, but an office whose every occupant was entrusted with a limited power to govern 'by and according to the laws of the land and not otherwise'."
So no, granting the Royal Assent doesn't happen in the name of King Charles III.
History can figure out who held the office when. Maybe we can’t sue either of them personally for those actions (which is what sovereign immunity relates to), but history can sure as shit remember which King took which actions. You think we don’t remember which George lost the American colonies, because it was the Office that lost the colonies?