Navigation: Onscreen trackcopy of original planned route
Navigation along track. Show track copy of original route
Navigation along preplanned track using auto-auto recalculation. Deviate from the original "parcours": -> the original planned trackrun is visually (partly) 'lost'.
Produce, save (delete later) an onscreen track copy, none active for navigation, solves that problem. Or: Before Nav start some extra actions to do, by the user ! (if not forgetting).
Q: Locus always should show a "greyed out" version of the unchanged original planned trackpath. When user stops track Navigation: Track copy is deleted too (track copy = temporary object).