Voynichese's letters

[Stefan Wirtz_2]

[..]
However, if we try to substitute Latin letters somehow, we get nothing, because this is not a simple substitution, because it's not a simple substitution, but something based on it.

Well then try something different.
Voynichese is not Latin, it is not German. 
Latin letters are a waste of time, but there is still no reason why this is not a „simple substitution“.

You are from Russia, should have some more ideas…