Check with Dex. He has that add-on and thought it was pretty good. Northern Sky is just one guy who put out PAKT for X-Plane and has ported it to MSFS2020. In my opinion, anything installed for Southern Alaska may become outdated once Asobo or Orbx or somebody does a comprehensive update to the area. However, until then (who knows when that is) it might be worthwhile.
Rod