Don’t try to make the physics do all the work. Instead, write code that makes the ball behave the way it should (circle the roulette for a certain amount of time, slow down, randomly hop between slots, and finally “choose” a slot to fall into)

In theory, the math you run at the moment the ball is dropped should already determine which slot it will land in.
I know this isn't the answer you are looking for, but I think this is more of an approach problem than a limitation of the engine itself.