I would also like to have minute marks at 2 minute intervals on the track. This is how we used to plan in early stage RAF training and was really helpful. On longer legs we would also put a position fix in abeam an obvious ground feature.When marking up the map on the ground we would plan for still air (which for SD would be useful for the printed out back up maps) and then adjust as necessary in the air ('I am now 2 minutes early' etc) Obviously in the air if SD could calculate it with wind then fantastic but even still air minute marks would be useful.
I have a PDF copy of the RAF elementary nav book if that's helpful.
Edited to add: I used SD on iphone this Sunday and it was fantastic. I definitely felt that my lookout was better as I had total confidence in navigational accuracy despite being near a lot of Class D and Class A.
Thanks!