3.5/5 – great potential, high risk if you pick the wrong link.

To update or manage the ZTE MF79U firmware , you can use the built-in online update feature or download specific regional firmware files for manual installation. Official updates improve connection stability, fix bugs, and enhance security. 1. Official Firmware Download Links

This is a massive Russian tech forum. It is arguably the only place with a comprehensive archive of ZTE firmware files.