They use Walker mag pallets on monster sized Huron mills at Airbus BroughtonIll-advised, and if you do take light cuts only as milling forces are much higher than grinding ones. You can block the part but using too much block can diminish the holding force of the part you're cutting. Another problem is of course you can not make any cut that projects through the part, and it will magnetise your tools, possibly even the spindle since there's a flux path through the cutter that doesn't occur in a grinding wheel.