Did you get the PDF version of the icon that I made for you?
Orthographic, perhaps? Although that alone doesn’t imply the Cartesian axes. Orthographic merely means at right angles everywhere. For architecture, typically, the axes are oriented N/S, E/W, Up/Down. But your desire of drawing a line in two directions simultaneously from a given point shouldn’t rely on the Cartesian axes, or orthographic conventions. A line by itself can be anywhere in 3D space. But for convenience, of course, we tend to have lines parallel at least to another line, and most frequently, parallel to one of the Cartesian axes. It would be handy, if given any plane (described in many ways, but two parallel lines does this) to be able to do the “draw-from-centerpoint” on that plane. SketchUp’s inferences already can handle non-Cartesian planes.