This is a privacy/security question: Is the modem of the Mudi E750 (EM060KGL...) "isolated" from the SoC/other hardware components, like on old Samsung S3 (see the replicant project)?
When it is not, the modem can be controlled my a magic sms (invisible by the user) and activate function in the SIM card like opening the browser to download a spy app, or browse the memory, and probably more. When it is isolated, the modem/sim card has no access to memory, it is like sandboxed. Is it the case for the Mudi?
The answer will allow me to choose between using the vpn function of the router, or of my smartphone vpn, for instance.