Work with .vcf contacts without merging into my computer's Contacts

macOS 11.6, Contacts.app 13.0

I have a .vcf file of Contact cards from another computer. I wish to work with them on my computer without merging them with the cards already in my computer's Contacts. Each Contacts file is ~300 entries, and there is some overlap. The job I want to do involves only the already-exported cards in the .vcf file, and not the cards on my computer. Getting my computer's Contacts.App to work with a different data file, or importing the new data into a separate Contacts.app group, or importing the new data in a manner that would subsequently allow me to remove the new data from my Contacts.app, would all be suitable approaches.

Apple's help pages don't address the issues of segregation or multiple data sources. Searching the net doesn't find a solution either.

How might I import these cards, do the work, and then be able to remove them? I could import the other computer's cards then work with them in my computer's "Last Import" smart group, but importation seems to require merging the incoming cards with the existing cards. I don't want to do that, because I don't see how I might remove the newly-added cards (when I'm done with the job) other than card-by-card manually.

As .vcf files are text files, they can be manipulated them from Terminal with any of the command line utilities available to manipulate text files.

Or one can temporarily create another user account and do it from that account. Then when finished delete that account after backing up the data to another location not within the account to be deleted.

Another method is to use a virtual machine.