Snap Cursor to Selected Edge Aligns the Cursor with the Edge

I know it's been mentioned that the custom Transform Orientations options are hidden away in the interface and that this will be improved for 2.8. I really use this feature a lot doing Viz for mechanical engineers. It's great that the new 3d cursor aligns with the face you click on, but it would be super useful if it could align with the selected edge. So, from Edit Mode, when you select an edge and Shift+S snap Cursor to Selected, the cursor could automatically align.

The problem with the current method besides it just being hidden away, is that I usually only have to move or rotate one or two things using the axis of an edge, but that custom Orientation remains in the list. So something that I had to use temporarily slows me down later when I have to go through a long list of orientations to find the one I'm looking for. This means that I often have to clean up this list so I don't end up with hundreds of orientations to sort through. Just going through and deleting a few dozen takes a good bit of time. If you could have a temporary orientation that is as easy to set up as Shift+S cursor snapping, the workflow would be greatly improved.