Ok, I realize that it is difficult and probably expensive.
For those interested, I tested the Silex DS-700 server these days. It is a good solution for CAT over USB, although the settings can be a bit tricky. I asked ChatGPT for help — hi! Just one recommendation: set the Default Gateway to match the router’s. Of course, you need a VPN as well; I used OpenVPN available on the router (TP-Link AX73).
73 yo9dl