Steve,
From the history files: The broadhead event was created to catch the interest of folks who's primary interest in archery is building hunting gear. It was used to attract bow manufacturers and give them a forum to fight for bragging rights. It attracted some interest for the modern materials bow people until Harry Drake entered into the fray for Browning Archery. Harry started creating one-off "broadhead flight" super bows that blew the competition off the charts and it dwindled into just another regular flight competition, except with heavy arrows. More recently, Broadhead flight seemed to have regained some interest with the addition of longbow and primitive events. I think it is kind of fun because the arrows are heavy and move slow enough that you can watch the flight, but I feel it failed it's originally intended purpose.
I don't think regulating the grains per pound would make much difference and it adds complexity to the equipment qualification process. It was busy enough at our last flight shoot making sure everyone's arrows were above a set number of grains. If we regulate grains per pound, then it still gives the advantage to the people with the longest draw length.
Alan