I hunted with a lab for years until I switched to pointing dogs.
Yes shorten the range will help as that is what I did. When I hunted with my labs I walked trails with the dogs working in the edge. That way when a charge and flush happened usually the bird came out to fly the trail. Gave me better shots.
But the lab is traditionaly a flushing breed.
Dog could be taught to do a sit to flush. That is when the bird goes up the dog sits and waits to be released. That might help with multiple birds if coveyed.
Just some thoughts
JW