Have a SPI flasher permanently connected, and a device on the LAN connected to that flasher, and to the LAN in order to automatically detect firmware version ch

Have a SPI flasher permanently connected, and a device on the LAN connected to that flasher, and to the LAN in order to automatically detect firmware version changes. When one is detected, dump the firmware update, and reflash your preferred version, and have it match the reported version of the new update. If you have a router in front of your modem, you could even make a killswitch that blocks WAN until the reflash is complete.