OTA updates over mobile network

[NicuD17]

Hello!
I want to start a project that will use an ESP32 and ESP-IDF.

The requirements are as follows:
- To use GSM/GPRS/4G to connect to my server.
- To have real GPS support, not the one from GSM.
- To read data from CAN-BUS and send it to the server every second via MQTT. I will use a separate CAN controller for this.
- Support OTA updates (over the mobile network, won't have WiFI). This is my main concern.

I don't have a hardware setup yet, but I looked for a few examples and found one that should do OTA over the mobile network with Arduino, but none for ESP-IDF. I really want to use ESP-IDF as I consider it more stable than Arduino.

Now, my questions are as follows:

I plan to use this board: the ESP32 LILYGO TTGO T-SIM7000G, as it has a separate antenna connector for GPS. (Please correct me if this is not true GPS).
https://www.aliexpress.com/item/4000542 ... ry_from%3A

What do you think about this?
Does anyone use this board?
Does it also need a battery?
How is the GPS support on the ESP-IDF?
Do you have a better solution?



2) Has anyone been able to do OTA updates over the mobile network?
Do you have some examples? Some tips?



3) I know that .bin files are usually downloaded via HTTP requests, but I was wondering if I could do them via MQTT, since I should already have the connection established.
What are your thoughts on this? Would I encounter some limitations of MQTT? Should I stick to HTTP?

Any kind of OTA examples would be helpful.
Thanks!