Offline Casper/jamf binary installs & ensuring computer enrollment

No, there's nothing built in to do this Hence the feature requests for things like enrollment self healing and other similar requests that are out there (I'll see if I can locate them and post back)

There are quite a few ways you can try to handle this yourself though. Things like a LaunchDaemon that is deployed along with the image that runs a script once a day to check something like-
a) Is the jamf binary installed? If yes, then b) Can i see the internal network? If yes, then c) Can the Mac communicate with the JSS? If yes, exit.
Or
a) Is the jamf binary installed? If no, then b) Can I see the internal network? If yes, then c) re-install a QuickAdd.pkg (somewhere hidden on the Mac) or, use jamf enroll commands to re-enroll.
Or.. other scenarios, etc.

You can also have the Mac query the Casper Suite's API to look for its own computer record via a script. If it finds it, it may be enrolled and managed. Not really a guarantee, but likely. If it can't find it, it certainly isn't enrolled. Juts another possible way.

As you can see, its easy to go down a rabbit hole with trying to account for every possible scenario. I would like to see JAMF help address the most common scenarios with something built in though.