lmao u think knowlist is the problem? knowlist is just a safety pillow for the client, the real and only issue is the client the server doesn't care it scales vertically
The client won't render more than a few hundreds of server object per region, not to mention what its able to render per fov, its well bellow 300, no matter the machine, runs similarly on a low end 2007 pc and a 2022 high end pc, so by definition a server wont break the 2k-3k barrier ever, (the point where players get frustrated with severe client performance and quit is probably lower than that).
now, the 5k+ online is a joke (not to mention the 15k+), its ape grade marketing for ultimate trashcan fanbois like achylek, who can not appreciate reality and rely on fake large numbers to play the server.
5k+ can be done only with world sharding (instances/channels/etc) there's no such implementation on and L2 server ever including the official ones, (WoW does something similar)
A decent high online number is something around 600 capped to 1400, you can claim that this is 3k+ the apes will believe this instantly (they like to feel that they are part of something important)