I hadn't contemplated the bi-polar map proposal before, but when I thought about plotting sunset azimuth and the actual location of the sun on the earth using the various flat earth proposed maps, the bi-polar one really stood out.
Tonight's sunset in Southern California is at 0226 UTC on a 285° bearing.
At that time, the sun will be over the Western Pacific, east of the Philippines.
As noted earlier in this thread, that would mean that the 180° longitude, light/space is subject to a "Pac-Man"-ish effect to connect, the degree to which depends on the latitude at the intersection.
Or am I misinterpreting this and the bowed lines of latitude are actually indicators of distortions of space/time such that my red line representing a "straight line" to the sun at sunset actually does curve around the upper edge of the disc and back down to the sun from the northern Pacific?
Once the sun crosses the equator in about a month, the problems with sun location and it's apparent view from the northern "hemisphere" becomes even more complex. I think this map creates more problems than it solves.
I would say your straight line to the sun is projected into an arc going around the north pole in a similar way as these latitude "loops", but never crossing the edge.
The edge represents a single point: 00°N 180°W.
More interesting is the 00°N, the equator. So the equator is not only the horizontal line at the middle, it's also the complete edge. So if your line does not cross the equator, the projection also does not need to cross the edge.
Indeed any line can have a corresponding projection on the map, without crossing the edge, no Pac-Man effect.
If a line has to cross the equator, the projection will cross the equator somewhere in the middle, and than for the rest of the journey will often follow these loops similar to the latitude loops (or the other way round).
This is quite weird and I cannot imaging, how the "spotlight sun" will work on this chart.
It's really amazing, that these Azimuthal equidistant projection are still the only maps FET presents. This projection by far have the greatest distortions among Globe Earth projections. Even this "Gleason Map" is nothing else than an Azimuthal equidistant projection.
For a flat world, it should be an easy job to provide a map, as no projection is needed.