Sorry i worded that wrong..
There is software available for FTM mode from zte that which was leaked years ago, but is in chinese and is of no use since we do not have official formatted files to upload via the app.
So we can not officially write in FTM mode, but FTM gives adb shell access to which you can send and write and pull recovery via adb shell.
If you can write a new recovery you will be able to get system access to root. What we did before was pull both the bootloader and recovery images and write the bootloader to the recovery and recovery to the bootloader.
This way we would have system read/write, but i would not advise trying that till you have a twrp/recovery to use to fix the phone.
The bootloader is based off lkbootloader so it has two actual bootloaders in one.