Quick fixes after playing with some others.
Headshot Healing Perk
Apparently the 'headshots heal keep' perk was healing for everyone's headshot arrows, not just the person who had selected the perk... This was not intended and has been changed.
Additionally, the bosses were becoming automatic full heals, so the perk has changed to "Headshot kills heal your keep", which should only significantly affect the bosses, as headshots kill most enemies outright.
Game Resetting
Previously if the host left in the middle of a game, it would reset for everyone.
This should now be fixed, but would like confirmation!