The Rex boards can be quite tough. With my good board I can boot at positive temperatures with a FSB of 660 without problems. (@ 1.71 volt @ + 27 ° C) Unfortunately, under LN2, the NB does not allow one MHz more. Such a pity, I thought I finally found a 700+ board ;-(
Isn't it a bit too risky for you using positive temperatures at 1.8 V for your NB?
What do you mean exactly with BarEdit? You can answer via PM if you like.