Well 3 targets per lane would get messy unless the faceplates were colour coded.
Sometimes the delay can be pointed to one slow group so that the next lane is empty, maybe the Marshals could ask them to step aside and allow a couple of groups to play through if they are quicker. Standing lanes tend to take all the time allowed (some sit, range, stand, wobble, stand, etc and 2mins is tight) and this year there will be 3 standing lanes and 2 kneelers so a bit more time used there.
The feeder lanes only work for the time taken to walk from the end of the course to the beginning, too many feeder groups and the backlog gets worse. Make the course longer or have a tea stand on the way back :-)
I can't see an earlier start being popular :-)