Location for extended non volitile storage

I have implemented a RAM buffer that I would like to save to the flash during a power reset (That is device controlled).

I think I have found the flash storage functions in the firmware (/firmware-develop/platform/MCU/STM32F2xx/SPARK_Firmware_Driver/inc/flash_storage_impl.h). Is this the correct set of functions? Are they accessible from the Web IDE?

My next question is where is the best address for this buffer? I am looking at the Electron Memory Map and I think the best spot is 0x80A0000 - 0x80C0000 which is marked as Factory Reset/ Extended Application.

Is there any reason not to use this block? I am only expecting to use ~15k.

There was a thread just a few days back that also refers to flash_storage_impl.h and that also addresses the Factory Reset block