In my opinion, there are better solutions than having GL/NA developers spend time on map tools.
I agree with and acknowledge Destraex' point about keeping the tools to a minimum.
The net is full of drawing and annotation tools, most of them free. The current in-game map, Siegfried's map, and Prater's tdamap.com map are all accurate for navigation over long distances. Take a screen shot, drop it into your drawing tool of choice (even PowerPoint) and notate away. Simple lines at fixed angles will give you the bearings you need. Text boxes and shapes for your notes.
IMO, there is no need to spend game dev time on map tools and note-taking when an overwhelming number of general-purpose tools exist to suit anyone's preferences, budget, complexity, style, etc. etc, with far more variety and features than an in-game tool would ever afford.
(I have the same opinion on requests for mini-games and furnished models of the captain's cabin. Go to chess.com while on passage, or take a video tour of the real Victory. Let our cherished game developers concentrate on features we can only get from them.)