Don't have my Chapman's handy or know the exact regs by heart I'm but not sure if agree with that or maybe I'm not understanding what you're saying.
Either way, the whole point is
not to see both lights at the same time unless you are heading straight on. Seeing only one light is exactly what gives you the direction of travel and seeing that light in conjunction with the white all around light helps you determine the size of the vessel.
And as far as the recall, I'm fairly certain it had everything to do with the mounting angle of the old nav lights and nothing else. The lights were angled too much and actually pointed upward instead of flat out toward the horizon. Like
@OUT ON THE REEF mentioned, I like the original setup better and still have the old lights on my FSH.If I ever get my other honey-do's done, I plan on getting in the machine shop and creating some type of custom spacer that will level out the old lights and bring them into compliance.