To continue Charles Coulombe's musings on how Catholics should recognise the Saxe-Coburgs:
Charles Coulombe lists some GermanEnglish monarchs who may have converted to Catholicism on their deathbed. Charles II springs to mind but he may always have been a closet case, like Sepharad-born minister Ben Disraeli the Marrano; anyway Coulomb is concerned with postStuarts. Coulomb claims Victoria wavered - but, truly wavered; she didn't take the leap, nor was she holding to the santa fé in private like the former Charles.
Her son Edward VII however might have taken that leap. Additional speculation swirls around George V.
The above stated, our Charles III - reports Coulombe - had his chrism blessed in Orthodoxy. That is not the same as Catholicism; but Orthodoxy is taken seriously in OnePeterFive, where we consider Anglicanism a LARP, which it is.
It may be that Charles and Prince William are tacking toward the Antiochene communion. They'll still not be Catholics, but they'll at least not be a joke.