As of writing, all missions in the game have the entire map available for players and AI units to use. Adding the ability for mission makers to limit the area in which players/other units can operate in can solve several issues.
Current issues caused by there being no map limits:
- One can easily fly way off the map in such a way that they can end up from one end of the map to another without being detected even with player Medusa(s) providing coverage. I think the fact that "Players flying outside the bounds of the map will be disqualified" is part of the NOCS rules signifies that the devs know that this is a problem. (See attachment 1)
- Players can order (naval) units to go off into the distance where they can't even be seen on the map anymore. In PVP missions where destroying naval units is a victory condition for one team, the opposing team can make it nearly unwinnable for them by moving the units way off the map.
As for how it could be implemented, make it an option in the mission editor where mission makers can choose if there are limits, where the limits are, etc. In-game, for players, give them a warning if they're leaving the playable map area and despawn them if they choose to ignore it. For other units, make it impossible for them to be ordered to go beyond the limits. The limit could be represented as a red diagonal pattern on the map (attachment 2).