@karma As I said in my post you can change the occurrence properties of the highest released subassembly. However, I don't know if doing so prevents recomputing of all physical properties of all components within that subassembly.
Whether assemblies are released or not, you should NEVER change occurrence properties of parts within a sub-assembly. Doing so would affect all places the sub-assembly is used. I've seen drawings completely messed up by users doing this.
Only change occurrence properties of the first level of your assembly.
However, what I have found in SE2019 is that you can apply an over-ride to occurence properties that enables you to change the option as it applies in the active file only, not anywhere else where the sub-assembly is used. Not sure how long this function has been available.
RMB on the cell and then apply over-ride.
I confused myself recently having turned off the display of some parts within a sub-assembly in this way, but they still appeared in other places.
I would think all you need to do is change the first level components to not be included in mass properties.
HP Z420 16GB RAM Quadro K4000 SE2019 MP5 on Windows 10 Pro 64.