Why and how the text could be Bavarian

[dashstofsk]

I am, of course, aware that this is merely a hypothesis

I still believe you are thinking too hard. This super-complex cypher theory would have been too awkward for the writer. The solution is probably more simple.

Complicated cyphers might have been okay for items of diplomatic correspondence that needed just to be made unreadable by any third party. They needed just to be decyphered once and read once. The VMS however claims to be some compendium of scientific knowledge, a reference book to be consulted often.

If the text is indeed meaningful then it would need to have to be easily readable. No hard algorithm to encode / decode. It would have been sufficient just to do enough to obfuscate the meaning.