you can see here a simulation test for an older customer project. i calculated how many parts fit into the machine before the bullet dynamics dynacache with 2 GB overflows. so you can see here the maximum possible number of parts that can be poured out with the collision geometry used. due to the perfect collision geometry (invisible, not rendered) simulation times close to real time were possible.
Whenever people show me Bullet simulations where the parts jitter, I know that the user has operated the Bullet incorrectly.
The jittering is not a problem of the Bullet. It is a user problem.
the one who is jittering is sitting in front of the screen. LOL