How about giving race organizers the option to have the “fence” in place for lead-ins. For slow-starters like me, busting a gut just to hang on to the pack over the first km is no fun and not reflective of the real world intent of a lead-in.
Ride leaders can you the fence from the start, The pace of the start depends on the Leader. Most leaders will start a ride nice and easy.
Races on the other hand start fast.