you can modify the event key in input, but you have to take the #ifdef #end parts out of the char/game.cpp and after this you are free to edit and re-purpose the event inputs for the server client work. this is maiet's fine chaos workart, things you try to use and change, ain't open in the rest of source even if you edited the main-project header and cpp.
search up the parts you are editing, and find where else in the source it's located at. and then you may able to find out there's a defines that work as restrictables.