Wow, that is exactly what I want to do, use the modem in my Cheetah V1 to a router.
And, I have a RPI-4 just sitting, doing nothing.
I wish to learn the inner workings, etc.
Sounds like a plan!
As for the Cheetah V2, it has been great, much faster for me, aggregating 3 5G SA channels with the new Quectel RM521F-GL modem.
I will try the same things I did in the old Cheetah V1 thread: