Control the physics simulation for few actors in the scene

It’s possible exclude an actor from a scene so each time the simulation occurs this actor remain stationary?

Then using a function executes the simulation only for this actor with custom deltatime?

I think your “remain stationary” concept would be best represented by kinematic (or static) actors. One possible approach would be to set all actors that you don’t want to simulate on a given tick to kinematic and all actors you do want to simulate to dynamic. I’m not sure whether this constant changing of actors to be simulated would mess with physx’s internal optimization structures.