Running lights location

I'm pretty sure the law reads something along the lines of the "forward portion of the vessel". On some new build motoryachts I've mounted them on wings/flats on the mast/arch about midships and never had an issue. Being seen is one issue, but just as big is to keep the glare/light away from the pilothouse to help watchstanders visibility outward.

I guess they have a set on the mast so they can seen for long distances in the open sea.
At the entrance to crowded areas, moorings, etc., they change to a low position which is seen better in closed areas
I had this arrangement on my yachts for many years sailing in the med .
I still have it on the current yacht

Having the lights forward of mid-ship generally makes the most sense (lets you know where the bow is), but that's not the law. It simply must be visible for the appropriate # of degrees, forming a full circle with the stern light. On many ships with an aft house you'll find them aft. With these sailboats, especially single handed racers, having them aft makes it easier for the helmsperson to know they're lit and easier to change a bulb if they're not.

I do wish people who design boats would spend more time running them. Between helm lights shining back from laid back windshields and nav lights washing out the view there's been too many times I'd have loved to meet the designer (in a dark alley).

I've designed a number of megayacht helms and it's not that simple.
-You're given a hull design by the owner
-You're given a helm furniture (dash) design by the interior decorator
-You're given a list of components that has to fit and work in a given space
-And about that time the shipyard is hounding you saying you're delaying the construction because you haven't turned in a layout yet, and you only got access to the CAD guy yesterday.
-Oh, and by the way, your already over budget, and the shipyard is just begging for a change order so they can overcharge the owner for something, but more importantly add precious days to the build contract, and you'll get blamed for it.
-And yes, you STILL have be be the center piece display at the next Ft Laud Boat Show!! The reputation of the owner, shipyard and the jobs of hundreds of shipyard workers are counting on you. No pressure.

Totally understand. My hat's off to people who can put huge projects together and keep them all in line. I don't work well with others, lol, so I prefer smaller projects where I can watch it all. Nothing frustrates me more than people who pass the buck, justified or not. The helm is a pretty critical part though, and sometimes some people just have to be told their ideas won't work. Interfering with the captain's view is one of those times.

46 CFR 111.75-17

I don't think that citation is on point to the OP's concern, but found it very interesting especially the part about duplicate light sources. Not sure I understand that, but was never very good at government speak.

This is a good point and it's probably why the racers only have lights mounted aft. I do know that red light is considered to be less likely to interfere with night vision, but I have not tested that on water. Red light is recommended in the city because it also is less disturbing to people so it tends not to keep them from sleeping.

If the widest point of the boat is at the stern, lights are visible from the front and there is no glare for the captain.

True but most boats I have seen are widest somewhere between bow and stern. I wonder if anyone ever put their running lights up in the rigging with shades below them to prevent their light being seen from the deck, but still visible at a distance.

Not uncommon, but when the lights are on the mast the lights are well above eye level. I think the placement of the lights in the pic is so another boat will know where his stern is if he crosses their bow to cut off their wind. Not like they give each other a wide birth.

If you'll notice the lights aren't on the hull, but instead raised above the level of the deck so the light can be seen forward and the arc is complete.