It would be great if there was a property of a cuesheet entry (or a special cuesheet entry) that marks the start of a leg. The cuesheet generator would also have an option to include the "Cumulative Leg Distance" in a column along with the other distances.
The purpose of this is for long rides it allows you to periodically resync whatever you are using to measure distance traveled with the cuesheet (eg. by resetting your distance traveled to zero). The end of the leg would correspond to something on the ride, a rest stop, control, etc, where you would also reset the distance on your odometer to zero or start a new lap on your gps. On long rides there are many reasons why your distance might get out of sync, including measurement inaccuracies. Its nice to be able to get back in sync with the cue sheet periodically.