Originally, the intent was to support updating resources too, the same way it is supported for MFGs and parts (checkbox on import). But we did not have time to implement it. As we plan to support it soon, we decided to leave it there in the pszx for now. The contet of the pszx is the entire loaded study (all components). You can put aside a psz, delete all resources and create a pszx that is much smaller.