Dear Peter,
You say:
"most family members would do"
I think we can agree on two things:
1.)
H.M. King Charles III of the United Kingdom is NOT a "most family members".
2.)
Either of us have no idea, what exact communications over the years, there has been between the two brothers Charles and Andrew.
Not to offend, you I find your idea to be pure speculation, which you are of course entitled to, but it needs evidence/proof before it is anything but that.
Conspiracy theories most often comes from "free" speculation with no evidence/proof.
If the idea is to undermine the British Monarchy in favor for a republic, I think it would more fair and reasonable to state, that you prefer a republic (, and you kind of already did that, when you said, you are republican, which is perfectly fine with me).
But to claim - and now nearly claim (using the word "most"), that sitting Regent of the United Kingdom should brake the laws to assist his brother; the same laws he as the King / the Crown, is head of - through the Crown Prosecutor, the various levels of Courts and their Judges, the government (remember it is His Majesty's Government), the House of Lords and the House of Commons), sounds ridiculous.
(Also have in mind at the same time, that being the King of the United Kingdom is not a one man show. The King of the United Kingdom has lots of advisors - especially legal ones.)