They are working members of the RF who as far as I know haven’t secured any commercial ventures or have any brand deals so not sure what your point is, how many royal engagements they do is totally irrelevant to the discussion in hand and quite contradictory considering your second paragraph.
I agree with C8H10N4O2 on this.
I think the supposed rigour with which the half in, half out rule is applied, is all a bit disingenuous tbh. I know Sophie and Edward made a balls up of it, but there is no reason to think that Harry would have necessarily. He was traditionally much better at doing all of the meets and greets than all of them put together imho. He was just naturally talented at it.
And everyone conveniently misses the point that with the system of royal warrants and nice deals with the likes of Range Rover and Fortnums and countless other purveyors currently standing as they are are, together with a fat annual income from the Duchies of Lancaster and Cornwall, £20 million a piece isn't it, KC and Camilla, and Catherine and William, don't need any overt commercial sponsorship to survive because they have massive covert commercial incomes.
I mean seriously, if you are receiving private rents and making money from Highgrove biscuits or whatever, why don't the King and William fall under the category "half in and half out?". Can someone explain the difference to me please?