The structure of the Voynich text and how it may be generated

[magnesium]

it will be interesting to see if there’s a way to sneak in a “payload” stream of plaintext letters or phonemes.

I have thought about it a bit.
My feeling is that a very verbose cipher (like your Naibbe) is almost indistinguishable from gibberish.
If you use several options and several letters for a single letter of the plaintext and/or use a lot of nulls then your text can any statistical properties because you can arrange your cipher text in any way you like. You just have freedom with redundant letters.

This way the signal may be lost in the noise unless you perfectly know where exactly  to search for it.

If Quimgu one day gives his algorythm then I could even try to sneak some meaning into it 

There is freedom, but only so much if you're trying to use syntactically coherent language as an input and keep that language decipherable (without resorting to huge amounts of ambiguity in the encoding scheme). Voynichese places very tight constraints, IMO, on the most probable ways even a verbose cipher could be constructed, in terms of how much plaintext language can be transmitted on average by an individual token.