So, now you have one hardware key that you have to manage either for all networks and therefore is both a single point of failure and constraint on availability

So, now you have one hardware key that you have to manage either for all networks and therefore is both a single point of failure and constraint on availability, or you need to manage multiple keys with the ensuing chaos. Kaseya was hacked through a patch so the type of protocol does not matter and you are trading convenience for management overhead that you have to deal with because all of your clients and likely many of your employees are not in your HQ. I have the bad feeling that this achieves security through unavailability.