this: "The unaccented Roman letters didn’t spell out the code. They were the spaces that separated the words of the real message, which was actually written in the glyphs and accented text." makes me think of a cyphertext within a cyphertext, something like an ancient form of stenography.

...maybe the symbold used as spaces are not actually random and there's another message hidden there, with another cypher, offering the writers of this "plausible deniability" regarding its existence: they could only give the way to decipher the first level of encryption and say that's all there is, while the really important information was hidden in the "space characters"...

(... now putting my tinfoil hat back in the closet :) )