Not sure about failure rates. Personally, I liked the board and blame myself. Things I should have done differently:
- Not do this at 3AM. Hardware breaks are (typically) more expensive than software compile breaks.
- Should have been more cautious while troubleshooting when board was energized.
- Should have wired fans to power supply instead of Fan 0.
- Should have tested buck convertor independently of the control board, BEFORE integrating.
- Shouldn’t have used the buck convertor even. Already had a 12V power adapter, should have used that for the control board, but 24V just for the motors. Ugh…
Guessing there’s more lessons here. Would appreciate advice from folks? Not ideal, yesterday I was drag racing, today, it’s dead Jim, LOL. There’s an opportunity here, and lessons for me, hopefully others benefit, and/or are entertained 
Cheers!