When you are drawing a compact PCB with hazardous areas (hight voltage) near low voltage areas it would be useful use not plated miilings.
I see that it's possible make pads with oval drill, but it's not possible make mounting hole with oval drill.
I think that this could be a simply way to solve problem, the best could be have milling tools and make millings as like draw polyline.
Thank you for the attention, i hope to give you a good idea.
Best regards
-- 20 Nov 2014, 17:47 --
I know, thanks to Alex, this request is just present in Dip trace, the way is posted in the topic "Milling on PCB".
Best regards