Yes, because your computer hosts every single file for Nexon. That's why it seems to take so much longer for you to patch.
Anyways, if you want to be technical, this is just as illegal and as mutch of a hack as OPK. You are modifying their client to give yourself things that other users do not have. It really is that simple. I feel that Nexon will ban for this, though, because if you can modify the .rez, you can figure out how to mod the rest of the files.
Like me; I'm thinking about swapping out the .dat files for worlds. I'd replace Snow Valley and Junk Flea and then do quarentine :>