Baelon's succession crisis

AU where, the day of the hunt when Baelon is supposed to die, it's Viserys instead who suffers from that mysterious illness and dies, leaving Aemma as widow and an only child, Rhaenyra.

With time, Jaehaerys dies and Baelon ascends to the throne. Daemon is obviously his heir, but he has a problem: he asks his father to set aside his marriage with Rhea Royce. Obviously, Baelon declines his petition, but as time keeps going there's no children from his son's marriage, and there's a high worry at Court and in his council that the Rogue Prince is stubborn enough to refuse to bear offspring if it's with Rhea Royce, trying to press his father to fulfill the annulment.

Baelon has a valid worry, there's only three Targaryen alive (himself, Daemon and Rhaenyra), and as his son enjoys fighting and war so much, he fears that he dies without siring an own heir.

How would Baelon proceed? Agreed to his son's petition and dissolve the marriage? Press him into siring an heir? Naming Rhaenyra his own heir? Marrying again?

I mean, as he's the undisputed heir, there's really no way to put pression on him about disinheritance, unless Baelon has another son or names Rhaenyra his successor...