Countersunk holes should (optionally) account for non-planar surfaces or angled holes

[Roger Maitland]

When making holes in non-planar surfaces a single central location may not result in the fastener being fully countersunk. To fix this, the profile of the hole should be projected at the surface at the angle of the fastener and the resulting wire should be used to calculate an extra hole "above" the fastener. This will allow countersunk holes in planar surfaces at angles off the surface normal to be correct.