This would be great addition imo. I saw a reply in another thread about being able to hear the line being ripped of the reel, i suffer from a lack of hearing in both ears so this isnt any help really.
of course you do learn to use some visual references when trolling but I still find that i am constantly referring to the map and spinning around in the boat to check heading and check rods.
Im surprised this hasnt already been done though, the compass seems purpose built to have a minimap there