So resetting's against the rules now?

[Hyrist]

Bare minimum solution is to not reset contribution on reset. I can see little to no downside in doing this.

I do: When do you stop resetting the monster? That system would be ripe for abuse by the players as a whole. "Reset farming" which could be attributed to something along the lines of Win Trading. There's no control as to when the monster should actually die.

I don't understand why these spawn instances can't just be points of interest on the map that are up for specific periods of time, and parties can click on it to engage the monster (An instance of said monster Duty Claimed to them, similar to Treasure Hunts) in their own fashion while the timer is still up. It would still be spontaneous, it would still require players to scouer the countryside, and it would still inspire people to make groups together - but it would remove these sense of unnecessary competition and the need to force one philosophy of play to conform to another by force of numbers.