Stone fruits play very well with almond, which is their cousin. Amaretti cookies are flavored not with almonds but with apricot kernels, because of their intense amaretto taste. I would poach your plums in amaretto, or, to avoid any alcohol (though it would cook out) apricot nectar plus almond extract. Simmer down till the compote gets thick, then use it as a warm topping for ice cream, rice pudding, or pound cake. If you want to go schmancy, top with crumbled amaretti or other almond cookies.
We had a lot of bum stone fruit last year - most popular uses were cobbler and crumble.
A bunch also got reduced to a saucy and concentrated compote, then eaten over ice cream or yogurt or oatmeal.
A less obvious use could be French canadian fruit ketchup - plums aren’t usual, but other stone fruit is often included - I have family there who eat lots of it with all kinds of things.
Tried and true for me with bland fruit is adding sugar and acid. You could roast, or you could pit, add sugar and lemon/lime juice, blend and turn into a sorbet/granita.