KR was suppose to be the Enhanced Client. Not sure why they changed it.
IIRC (based on conversations with former devs), they changed it (more like abandoned it for the SA Enhanced client) because EA Japan had committed to a 2Q 2007 release of KR in Japan, with a physical shelf presence, and EA forced its programmers to release KR at the end of June 2007 to meet it, despite that KR wasn't really ready for ALPHA testing when it went into open Beta, and needed at least 6 months more work to be ready for Beta, let alone release.
This was followed by the uber-buggy KR having to be updated simultaneously with the CC for in-game additions, and they were adding new bugs for every one they fixed because of the new content. They effectively kept losing ground on it, to where by late 2008/early 2009, it was easier to start from scratch from where KR was during internal testing in 2006, and redo everything after, to make the SA client. This included abandoning the new, prettier, graphic system for something in-between CC & KR, as KR's graphics were so system intensive that they were causing issues with users' computers. (MASSIVE lag issues, among other things).
Ironically, modern computers today would probably laugh at those requirements, but they were way too ambitious 12 years ago, when you consider how much memory was being used to try to convert a data stream meant for 1990s 2D Isometric on the fly to a modern graphic style in the PLAYER'S computer. Even today, when companies "remaster" a game, they typically rewrite the existing game for the new graphics package, not stick the old code in with a real-time converter.
