It’s difficult to use a mouse to draw a reasonable line on the airport diagram to highlight the taxi route. A cool feature, if it’s even possible, would be to have Google Map style snap routes. It would work by clicking your starting position, then ending position, which would result in a “best guess” taxi route. If it’s not exactly what ATC gave to you, then you just drag the route (like in Google Maps when modifying a suggested route…) and the route “snaps” to the taxi way you drag it to. Easy to quickly set up the route instead of shaky mouse drawing. As an added cherry on top, a few user selectable route highlight styles could be used such as a hard line, soft edge line, opaque highlighter line, etc…
Just a suggestion from someone who doesn’t use this write on the chart feature because of the current interface, but would if it were available as the above “snap” interface.
Cheers.