hey on your GB board, when you fail at very cold temp, just press power button as rapidly as you can possibly more than 1 time, like tap tap tap lol. also BCLK=CBB and CB helper, only like 103mhz is needed.
Also i tend not to use the benching BIOSes, but it shouldn't make much difference. I think Sniper3 has better CBB behavior than UD3H, which i think is worse than UD5H. depends on the benching tho, E1>E0 for better CBB behavior.