So far koreans are the worst gaming community i have had the displeasure of being a part of. If you are a foreigner you will get ksd at grinding spots.
A typical situation that happens is you are grinding in a spot, someone shows up and starts fighting you for mobs, this might go on for 10 or so minutes before you are like ? or kindly ask them to change channel, they won’t they just keep fighting you for mobs. Finally you are like whatever and change channel yourself and find to your dismay that all the other channels are empty.
But at the same time if you do get in a korean grinding party, they will let other koreans take portions of the map and not say anything to them until there is nowhere left for the party to grind
Iv’e met plenty of one offs that help me with a quest, or try to be friendly but they are few and far between,
tl;dr koreans will ks english speakers, but will inconvenience themselves to not ks each other.