I am using it in a commercial IoT project where the MCU flash is split into 2 parts: usual program area and a file system to store persistent and temporary data

I am using it in a commercial IoT project where the MCU flash is split into 2 parts: usual program area and a file system to store persistent and temporary data like ota. The main purpose is flash usage leveling which especially critical on MCU-internal flash, and as a bonus, it's just neat to have a real filesystem where you can work with FILE*. In about 2 years in the field - no issues.