"Save as new" in Route Planner: Good, BUT:
Why not just use common behaviour as in most applications, "Save" vs. "Save as..."?
"Save": a) If new+unsaved track, effectively be a "Save as...". b) If editing an already saved track: Instantly save without asking.
"Save as": Ask for name etc. before saving in any case. Take over old name if track was already saved. If using the same name, ie you effectively overwrite, then it should ask for confirmation (currently does not).
Keeping the undo steps (not flushing them) after save is VERY nice to have. At least when allowing save without confirmation. But then it would need to stay in planner obviously.