The thread you're linking to would suggest this has nothing to do with window swapping, it's all about the macro you're using to change the game's graphics settings. Which happens to occur during window swapping. If you remove that behavior from your Window Swapping and it's instant (as configured in your Window Layout), then let's not talk about "window swapping
lag"...
That would be a graphics reset/change in WoW caused by one or more of the commands in your macro. Figuring out which ones it is will be necessary to eliminate the
lag.
Turn Key Maps OFF to disable your Settings High/Low Mapped Keys (so you can do the macro itself in game yourself instead). If you do this and press Ctrl+Alt+[ and Ctrl+Alt+] to switch back and forth, you want that to be instant, and it sounds like it currently isn't.
I went ahead and dropped your macros into my config, and by manually using them I see that it isn't instant and I also see a "blue wall."
By taking it line by line, I have identified something that definitely causes the described behavior. And you can try it out by typing it into the console! Enter these commands in the console, one after another, and observe.
/console farclip 1057
/console farclip 185
Removing these lines removes both the blue wall and the
lag. You will not be able to change the clip plane without this behavior in this build of World of Warcraft, as far as I can see so far (this happens in both DirectX 9 and DirectX 11).
Enjoy.