I'm slowly figuring out that the user interface part of the Megarevo is a pretty standard STM32 controller that you'll find in a lot of embedded devices, which jives with wanting to keep manufacturing costs low and standard. It definitely has enough processing power to drive the unit. Think of it like an Arduino device.
It does emit info and error messages on a console, but I haven't checking into how to read those - the 'stream' firmware updater might have the capability (with the ARM and DSP buttons - they launch a different, but blank screen).