Nice work! Sorry to ask again, but could you post a schematic in pdf, png, jpg, something we don't need Eagle to read? And you wouldn't happen to have a BOM?
I'm holding off at this point simply because of the parts cost, but perhaps the cost could be lower with other components that would also work? E.g. those fets are spendy and add up fast x6. As you noted, the smaller AVR's cost about the same, but there are other uC's like stm32f103 that are far cheaper and faster, etc.. Don't be afraid of SMT soldering, it's really no where near as hard as people think, I teach a class in soldering from this presentation, and slide 18 and 19 (after learning to solder in the prior slides) along with the video are all most people need to solder fine pitch with regular equipment.
https://docs.google.com/presentation...g470e74144_041
If the parts cost can be reduced, I'd be willing to seriously consider making a kit available with a professionally made PCB.