Good idea, but needs an overhaul of dockerMan to accomplish.
dockerMan when saving the my* templates does not save any tags that are not basically already present in the template presented to the user (it does add one or two extra though like date-added / installed). eg: if you compare the templates that are stored in /var/lib/docker/unraid/community-templates (which is what CA passes), they have far more tags present than what is saved post install in /boot/config/plugins/dockerMan/templates-user.
Personally, I would like every tag that is passed through to dockerMan at install to be saved with the user-template. (If only for future possible additions to dockerMan)
Although not exactly what you're talking about, CA does have a "branch" feature which allows a single template to completely modify itself (what is passed to dockerMan) according to user input. ( ie: if binhex implemented it, he could have a single sabnzbd that would either install the regular version or the vpn version, and the appropriate environment variables, repository, etc would all be populated accordingly), but that only works during installation.
Net result though is that because of this, FCP has zero clue about any extra tags to designate this because of how dockerMan operates.