This sounds fun to play with and get feet wet in HDL, but it's only a lattice ice40, I have no idea what you'd seriously do with this. Usually ice40 are used as glue logic, or multiplexing/buffering a bunch of ADC/DAC chips so the processor can do large data transfers instead of a bunch of tiny ones.

The website claims hardware acceleration and... I doubt they got timing closure on the soft CPU at anything greater than 100MHz and you still have to get data to/from it at likely 30~40 MB/s via an SDMMC bus.