If your munge happens almost instantly then you probably having the spacing bug (could happen even if the munge isn't fast). The bug being there's a space in one of your folder names and the batch munge scripts don't handle it properly. Reinstall your mod tools to your root folder: C:\ and/or apply the fix (I don't remember its name, check the Everything You Need sticky topic).

What you're trying to do is possible, so don't give up thinking it's not.

No warnings & no errors ...

@[RDH]Zerted: Ok, I'm going to do this the next days, still working on a map I'd like to finish first