I’d suggest mixing small chunks into the meatballs themselves rather than just adding to the sauce.

One of the reasons pineapple works on pizza (for those that like it) is the high heat of the oven toasting the pineapple. You won’t get that same effect by adding it to a sauce. Adding it to your homemade meatballs means it can get seared in the frying pan when you precook them.

Or you could sear some pineapple slices before adding to the sauce.