instead of using system timescale create a family (or multiple families) of all objects that should be paused and use set object timescale.
This way only some object will be paused and system timescale etc. works normally.
Thanks for the suggestion, but the pieces in the game are also creating using timeframes. Like create object after waiting 1.43 sec, 2.54 sec, 2.75 sec etc. to match pieces with notes in music composition. So if I'll set time scale to 0 for the pieces they will spawn anyway but not move