In the future, we could explore offering this solution from My OSMC. I don’t know if anyone on the team has a 3G dongle, but I will enquire.
For now, it would be good to explore the possibility of setting it up via the command line (connmanctl), so we can work out how much work (and what) needs to be done.
I would start with installing a couple of necessary packages:
sudo apt-get install ofono usb-modeswitch
Now, you can run
sudo connmanctl
If your modem is picked up by the kernel, you should see
connmanctl technologies
list 3G as an option, in which case you should be able to enable it with
connmanctl enable 3g
And then you’re on your own, because I don’t have a dongle at hand.
Sam