I looked at the first model, will look at the second one in a bit.
Since you are setting zero at your table (top of spoil board, I assume), I would recommend breaking your roughing pass into 2 parts (a separate process for roughing and finishing). If you want to stay... .050" off the bottom of the part for the roughing pass, set the "bottom height" at +.050", then just duplicate that pass and on the next one set the bottom height at zero.
I'll look at this more closely in a bit.
PM