Thanks for the feedback. I like the localizer arrow suggestion, will make it look something like that. And I'll move the label to the start rather than the end. Magenta would get lost if the flight plan overlapped, but I hear you that yellow isn't a good choice. I'll play with the colors. Few points I want to clarify:
1) Currently the runway is a fixed length regardless of zoom level, so no matter how far you are zoomed out, the extended runway will be obvious. Would you prefer this to be a fixed distance, such as 5 nm? That would be an easy change, but would only be visible when zoomed in. However it would also, I think, provide a better target for your arrival plan.
2) Only one runway approach may be selected. IE, if runway 17/35, you pick "17" or "35" - and the selected approach is extended. So every airport will require a selection.
Thanks,
Walter