MKRWAN arduino board firmware upgrade?

Hello,
I have programed my MKRWAN board with the MKRWANFWUpdate_standalone sketch, which does an upgrade of the STM32 code inside the Murata LoRa chip.

This STM32 firmware is stored in a fw.h file, brought by the MKRWAN library.
But there is no mention of where we can find updated firmware from Murata for its LoRa chip.

<extract from MKRWWANFWUpdate_standalone.ino>
 * To generate it after a firmware update, execute
 *
 *  echo -n "const " > fw.h && xxd -i mlm32l07x01.bin >> fw.h
</>

I would like to know the source of this firmware, and to know more about the current firmware as well ?

I found this site:

Seems it is the source code of the Murata chip.
Binary versions are available in the releases directory: