kill NPCs outside the event zone

Players can kill NPCs from the ground and become, if I understand correctly, owner of the event without doing so afterwards.
Which means that the event is blocked for players who would actually do it (by killing NPCs in the event zone).
FYI, a player was able to kill an NPC at a distance of 934 meters...
Unless I didn't look carefully, I didn't find an option in the config to prevent shots at NPCs from the ground.
Is there a possibility of adding it in a future update?

Changed Status from Pending to Work in Progress

Fixed this in the latest version

Changed Status from Work in Progress to Closed

and thanks also for the button