Maybe the software needs a bigger time delay between the voltage steps, to give the chips and temperature more time to stabilize, before the next step up.
This may also help with the low temperature start up problems some users are reporting. (gentle pre-heat)
The issue I am seeing doesn't really have anything to do with the voltage steps. What is happening is that PWM for the first phase is causing the second phase to turn on prematurely, which is causing a whole host of issues.
Problem with burn-in is that I would need CPU coolers and PSU. This boards is not ready to hash and it is up to 180W. That is about only 50W less then 16 chips Cointamination. So I don't have enough for any kind of long test. I don't think fuses can handle it too(over 10KW). Every board will be test run but that is it...
If you'd like I can give you a version of the firmware that will limit the power to the board. You'll only end up with 30-32GH/s, but the power draw on the 12V rail will be closer to 100-110W.