"Diagonal" mode checkbox for blueprint grid configuration

[JasonC]

I would like a checkbox in the blueprint grid configuration, perhaps underneath the absolute/relative radio buttons that, when enabled, forced placement to be corner-to-corner on the grid instead of edge-to-edge; i.e. forced diagonal placement of the blueprint.

This would make the grid useful for things like diagonal rails and walls.

Currently, for things that should be placed diagonally, it's not really possible to take advantage of the grid feature because you end up placing an extra blueprint if you try to drag them diagonally.