[pd0wm]

Have you experimented with modemmanager/networkmanager to handle the configuration of the modem? For me that has worked quite reliably across a pretty large fleet of devices with a Quectel EG25 (qmi over usb).

Regarding FW updates, have you tried opening a support ticket with Quectel? For me they have been extremely responsive and helpful, providing extra documentation on special AT commands and stuff.

[geerlingguy]

I have not—that was what I was trying (mmcli) early on in my exploration, but I kept hitting speedbumps, so switched gears to configuring the modem over TTY and using QMI utils directly.

I would like to use modemmanager though, it _seems_ like it's the nicer path.

[pd0wm]

With modemmanager you get a lot of nice stuff for "free", like automatic reconnect, DHCP, good logging, and an APN database (useful if you don't provide your own SIMs). It also allows you to easily set up correct priorities between WiFi and LTE, both for routing and DNS. Especially DNS is something I didn't think about at first, but the DNS server provided by your LTE connection is not always reachable over your WiFi/ethernet connection.

This is the config I'm using: https://github.com/commaai/agnos-builder/blob/master/userspa...

You can run modemmanager in debug mode, which allows you to send AT commands over dbus (or mmcli) in case you still want to configure some stuff manually or get debug info.