And your conclusion about the hub in modem mode being far less stressed would seem perfectly reasonable and hence needing fewer (if any reboots).
What I do find odd are two things, firstly Megan’s post just above in which she says that the hub hasn’t been rebooted in two months is in direct conflict with the OP’s contention that the hub rebooted less than a week ago at 3am, and has been rebooting from time to time due to a kernel panic.
So something isn’t right here, either whatever diagnostics VM ‘s forum team are using, simply aren’t reporting the truth, or what the OP is reporting as a ‘reboot’, isn’t!
Secondly, of course, the idea that the hub ‘needs to be restarted every once in a while to ‘reset the data(?)’’, is, of course a nonsense, unless, as you speculate, the VM firmware, isn’t really very good.