Sure I can. Modem's firmware is split into two parts. Linux OS running on ARM CPU and modem's modem FW running on hexagon cores. It's possible to modify ARM CPU

Sure I can. Modem's firmware is split into two parts. Linux OS running on ARM CPU and modem's modem FW running on hexagon cores. It's possible to modify ARM CPU code without affecting modem's operation much at all. ARM CPU just takes care of some audio/USB and such interfacing tasks. It's laregely free to run your own tasks. The manufacturer even allows customers to build their own userspace code for the ARM CPU inside the modem and extend it this way as part of quectel open linux SDK. Anyway, the original issue was about notifications, and ability to implement them without consuming too much power. And one of ways to do it is to extend the modem this way.