I don't think this will be abused.
Only by n00bs perhaps.
People can also choose to spawn as a cop or medic @ the police station or hospital.
Those places are less safer than @ the duel arena because players can use there firearms, but when there are people present @ the duel arena and a player wants to leave that place, is the player sure nobody with full armour & all will chase that guy?
If you take time and think about it, it can be abused anyway.
you go to duel arena, write duelrespawn, leave kill & get killed, respawn at duel arena and write duelrespawn again?
That code: IsPlayerInArea sure might come in handy!!!