Sounds like we've got a similar configuration and intention (split screen into two layers, one on top the other on the bottom). I got mine working using maximizer without configuring keyclone to do anything.

The only thing I did differently than you (or maybe you did this already, it's unclear from your post) is that I modified the config.wtf in each of my C:\wow<num>\wtf directories to force the new resolution.

If you've done this already, could you post the config.wtf from each account (sanitizing it for proprietary info of course)?