I checked 2 times. Noggit is taking MPQs from the same client dir i test MPQs on. But hm, would it be possible that wow.exe is using a different data/client path (taken e.g. somewhere from registry) and not the data folder within the dir i'm running it from?
EDIT: Scanned whole registry, removed a few entries (old paths where client isn't at anymore since ages). Didn't help.
I give up. After more than 30 hours of testing various tricks and ideas I find it impossible to edit blizzard maps with Noggit (in a way so edits are visible in client at least). Even though i have seen working maps like that but maybe this is just hidden and not released to public like me, takes some Noggit mod or saved ADTs post-processing or whatever. That seems the only answer here. Maybe someday i will be able to. Thanks for your time again.