He's got his own patronage and actually does more with them than the Queen I read somewhere. He used to get really involved rather than just lending his name on the letterheads. Not that I'm criticising the late queen. Just that king Charles was actually involved in things more than most royals were with patronage. I think we never gave him enough credit. A bit like Duke of Edinburgh. They both did a lot more good than commonly understood.
I think he'll keep his own patronages like every new monarch would have done. Quite right too IMHO. What user is patronage without a patron being interested?