The panoramic map and the Mt. Shann glyph do look similar but are not connected. I do agree with you that the panoramic map could be leading us to the location of the third meteorite or collectibles/random events found at the points of interest. My vantage point on the panoramic map is based on line 2 (Orange) which is drawn at a 80 degree angle and crosses over the northern tip of Flat Iron Lake.
The Mt. Shann hieroglyph shares similarities with the Mount Chiliad hieroglyphs and the Famous Hamburgers logo in GTAV. Like the Famous Hamburgers logo, the Mt. Shann hieroglyph has seven rays and an arrow. The only difference between both of these mysteries is that the Mt Shann hieroglyph reveals the location of a UFO using an arrow which points directly at the tip of line one (left to right) and the Famous Hamburgers puzzle reveals the completion percentage (100%) needed to view the FIB UFO(s).
