I can only tell. That for instance brew/
mif folder is
not important or interesting.
Backup of this folder is useless. As encrypted...
But there are several methods possible to try.
EFS is also known as "CEFS". There are Tools out. Which can read it like an Imager.
NV items are an part of EFS and stored in folder NVM.
I suggest again. Before not Firmware is leaked to have an chance to repair self.
No tests... as it could be to risky something to replace/move or delete...
Also dangerous to create folder with
same name. As few folders are invisible...
Depend which subsys commands are used...
It is like Windows. System files/folders are under control of OS.
On running OS you can't play with such files...
On U960 it is called under control from
AMSS. This is
Qualcomm related.
Thank you for support.

Best Regards