You can select both linked files (RVT or IFC) , and current project as target for either building or service elements.
Where you go from there is up to you.
A quick method for getting an overview of void requirementes is to use the DirectShape option.
Then create the provisions as needed using shapemode Normal and/or BoundingBox.
You could create a new empty Revit project file to coordinate all void requirements in the project.
This could its own central file create for the purpose.
Just link all applicable models (RVT or IFC) and do the void/provision calculations.
Or select your project as either "Service run project" or "Building element project".
And perform calculations using a linked Revit or IFC file as target.
When the building element project is the same as the current file, then shapemode Normal and BoundingBox will create the actual voids.
(Shapemode DirectShape will still create provisions.)
You can edit the provision familys to a certain degree, such as 2D symbols,
provided you dont change the family name, existing parameter names and basic functionality.
(Voids or provisions for such created by shapemode "DirectShape" are not familys and cannot be edited.)
When exporting to IFC its good practice to store the IfcGuid in the Revit file.
This is an option in the "Autodesk IFC Exporter" found on app exchange.