I frequently forget to track my shot on the tee, and only remember when I arrive at my ball on the fairway. What's the best way of retrospectively recording my tee shot - should I use the "Add Tee Shot" option while I'm standing by my ball on the fairway? If so, will it capture the location of the tee and hence maintain a record of the length of my tee shot?
Yes, do that, and then reposition your location as to your best guess where the tees was located on that day. You'll be close enough, or even better than the inherent error in the GPS positioning had you tagged while you were standing on the tee.
As for frequently forgetting to tag while there, make it a habit of tagging while walking by the tee as you first walk up to the it (even though you may not have the honor). Then everything's out of the way when it is your turn to hit. My .2 cents