I had a client once who used a USB SIM modem as an out of band alert system set to text IT staff if certain monitoring thresholds were detected connected —useful if the Internet post were damaged. At the time, 10DLC wasn’t a concern in the system was reliable (but low volume.)

Would such a system be untenable these days? Is it possible to provision a physical SIM that cannot legally be shut off, but is whitelisted to only 10 consenting numbers at a time?

I feel like people can fly under the radar on individual small scale use in-house, but the second you're trying to run a full scale public facing service with hundreds of thousands of messages originating off one SIM card you'll get lit hard.