Deselect when importing from another database or file

I don't want to import users who are used in the source process.

Support told me, “Users who are used in the processes to be imported—such as creators, etc.—cannot be deselected during import. These must be imported as well.”

Yes, my colleague told me, “After the import, there is an option to merge imported users with existing users. This will replace the newly imported users,” but I want to avoid this source of error and not have to import “wrong” users in the first place.