Yes, it is a STM32F... on the mainboard of the copter and can be flashed (FW update). The firmware is product-specific. I do not believe that you can use CleanFlight. You will get problems with the addresses for sensors, transmitter ESCs and so on.
It would be worth to test it when CleanFlight can change all those parameter, but the chance that you burn it dead is very high. To do such experiments need deep knowledge in both HW and SW.
be HE