Ed, I see you defined mine_slush at 0.4*difficulty, is that correct afaik it should be something between 0.10 - 0.25 if I remember correctly.
I heard something like 15%? I think with the *4 factor (copied from the default scheduler), it ends up around 11%, since it's 1/4 of the default threshold of 0.435*difficulty.
Will add in "penalty" option to user.cfg and then people can muck as they please...