I developed an integration for LTE for work a few years ago for a linux server, I found the experience the same in how little clear information there was. We tr

I developed an integration for LTE for work a few years ago for a linux server, I found the experience the same in how little clear information there was. We tried quite a few different cards, though I can't remember the one that ended up "working" (the project wasn't ever deployed). I could not get qmi_wwan or wvdial to work consistently, which was crucial as if it went down someone would have to physically intervene. I ended up using plain old pppd and chatscripts, which was especially amusing to me as a late millennial who never expected to use such antiquated technologies. Another fidgety thing was the SIM pin, especially given the threat that multiple failed attempts to set it would lead to a lockout. That being said, it is far simpler to just get an LTE modem with ethernet ports and let that take care of the connection.