Interesting, I never got the x42 multi working with my setup. Mind to share the trick?

I think it just might be the board mate, don't ask this old dog for tweaks or tips... this was done at -105 temp pot, so around -80°C for the CPU, didn't have a lot of LN2 in the Dewar....

Grab a good board man and thrash that CPU... I just ran these to add some colour to the article