How to save sim resources?

Hello! I have used Sim ready assets and custom warehouse model that I have gathered up.
I setup the shelters as collider and press play in Kit 107:

It simulates the box falling, great!

All the other sim ready assets on the scene are also being simulated after the play is hitted:
They fall just a tiny amount, like 1 centimeter and stay on the shelves and on the floor.

I think that all of the other sim ready assets are taking not needed resources from my Ada-6000 workstation.
How can I just drop the other boxes to hit the shelter and floor and stay there fixed, not being simulated at all?

I believe there is no need to control the time values of the simulation ( first sec only or so ) that is too complicated for this need. I would imagine the good old Zero Gravity tool is one way here, but with these Sim Ready Assets, what is the correct way?

Well that is the point of using Sim Ready Assets. They have physics set up and enabled by default. If you want to save resources, those same assets are also in the normal Nvidia Assets browser, without the physics applied.

Alternatively you can just use the physics authoring toolbar to turn off physics for objects you do not want to be involved.