Done it. Not working.
I think that this is not connected with component sleeping mechanism at all.
The main difference is that if I force (via settings) my component to actually sleep and then I set this component’s rotation speed, this rotation speed is subsequently zeroed by the engine (usually it takes about 3 frames).
But in the present situation the speed I have set can continuously be read by use of ‘GetPhysicsAngularVelocityInDegrees()’ function. It is not zeroed.
Moreover the ‘RigidBodyIsAwake()’ function returns ‘true’ if called for the component.