It's specified for CS:S because I originally requested it for CS:S (see here:
http://forums.alliedmods.net/showthread.php?t=103413). He's already aware of a request for a cvar to change the menu functionality to chat, rather then appearing in a secondary window. However, due to the way he wrote the code, he has to completely rewrite his functions to take into account the current KeyValue so I'm not sure when he can get around to it
.