From another tracker:
"I had a feature request in mind for a "route log" feature, but I think it fits here. This would be a track recording mode where only those trackpoints are recorded where I turned/where I was told to turn.
Another option would be to omit track points on a long straight line (e.g. a motorway).
One aim would be to save space in track recording, another to be able to use tracks as routes.