Just an idea for way down the road: The ability in PCLib to define an arbitrary shaped holes, cut-out lines, slots, etc. Reason: There are devices such as the ST PowerSO-10RF package that have "submerged" mounting configurations - where the "pad" for a component (in the PowerSO-10RF case, the 'Source' of the MOSFET) is actually on the bottom layer of the PCB to allow direct mounting of a heat-sink. There are also critters such as heat-slugs, etc, that are not round. How: Similar to the "Solid Area," "Copper Region," or "Pad" function - so it is possible to define area that needs to be cut away (and possibly even how deep?) during the hole drilling process. Something similar to Altium's "Pour polygon cut-out" Why: Creeping featurism.