So it comes out of the top, and only the top, at a 45 degree angle. Questions about this:

For sync purposes, and disregarding occlusion, is the best position for the IR slave lighthouse ON this line, or anywhere inside it?

Is the top side of a lighthouse a unique or preferred from the other sides regarding IR sync, or could all four sides have a 45 degree reference laser coming off them? If the wall mounts that ship with the vive imply a sideways mount, wouldn't HTC have warned against it?