My family think I'm a monster, but it was really nice. I chucked a load of parmesan on too, which really counterbalanced the sweetness of the plums nicely.
We already did:
https://www.doradcasmaku.pl/przepis-truskawkowa-pizza-370420
But so did the Americans:
https://cookieandkate.com/strawberry-basil-and-balsamic-pizza/
I wouldn't try plums or strawberries on pizza. But that's mostly because I hate fruit. Although I like pineapple on pizza and I've had good pizza with pear.