With how big of a deal dying is in this game due to the penalties that come with it, I think that the game needs to launch with a right click duel option.
People want to fight their friends. People want to practice PvP. In a PvX game, all the more! But without a clean option to duel people with no accidental deaths, there is no good alternative.
My suggestion is to take WoW Classic's approach to it. Simple enough, duel starts, there's a "duel" range where if you leave, you forfeit, and if your character hits 1hp, he stops taking all damage, and both unflag immediately. Then people can heal up and go again if they want to, or go on with their day