Anecdotal post . . . .
I use Mikrotik's, A couple of years ago I got a Visible service and ended up 'usb tethering'
Use an old Android device for 4G / LTE Internet on a Mikrotik router.
blog.ligos.net
via a throw away $50 chinese Android phone, no hot spot they know about, no 'alien' hardware they could blacklist, It worked . . . .
Then it just stopped working . . . .
After fighting with Visible for a few months/phones/routers and still not working . . .
I switched to MintMobile, Same method, it's just still working . . . .
My guess is they monitor usage for 'acceptable use' and most users won't be 'traffic-ing ' all day and night to all sorts of connections, thus you become unwelcome . . .
JM2CWAE