Enables
you to define whether to optimize clearance for a Via Pad that is
embedded in an SMD Pad. This variable has four modes. 1 -
(Default) - Optimize clearance for both mechanical and laser vias that
are embedded in an SMD Pad. (Laser via is a drill assigned the
attributes .drill = via & .via_type = laser.) 2 - Optimize only mechanical via 3 - Optimize only laser via 4 - Do not optimize either