I think if you want to promote responsible bowhunting, you’ll allow a broadhead area. people can bring their own targets to cut down on costs for new ones all the time. IMHO practicing with broadheads is absolutely crucial to confident accuracy in the field, and many hunters do not have a place to sight in with broadheads. Liability may be a concern, but realistically no more than any of the other activity at a range. Make sure there’s a hard-fast rule about zero “hunting” activity and zero tolerance for anything that can be perceived as such, as well as any ramifications for shooting broadheads outside of designated area. But providing a place for people to (99% of the time) responsibly practice with broadheads is promoting good habits and shows your bowhunters you support their success.