Great detective work re the azimuth finding for the glyph, but I believe the link to a sextant is tenuous at best. The author says it can, of course, be turned sideways to measure an azimuth with respect to an arbitrary meridian. That’s not correct. The tool for doing that is an azimuth ring sitting on a compass which allows the user to obtain the angle relative to north (the azimuth) between the user’s local meridian and a landmark.

A sextant can be used to obtain the relative horizontal angle between two landmarks, but it is much easier to use an azimuth ring. A sextant is designed to be used vertically. Holding and using one horizontally is difficult and time-consuming in comparison and is probably a less than a 1% use case, used only during the training of apprentices as a theoretical exercise (source: professional mariner for many years and daily user of a sextant back in the day). A comparison would be using a screwdriver to drive in a nail; you could do it given enough time, but a hammer is much easier.

I believe the explanation is much simpler: the glyph simply represents a variety of angles measured from north (the common meaning of azimuth) avoiding the use of any lettering (like “N”) or the use of a compass-like symbol which would be difficult to represent at such small scale.

Also (pedant warning for another poster) Polaris is not the brightest star, it’s around the 40th and has no practical use for navigation other than “north is roughly that way”.