The VMS as a possible chain encryption ( Mod 23 ).

[oshfdk]

It is possible to achieve any entropy figure via mapping. Generally, it's possible to match any single statistical metric of Voynichese with almost any cipher using some post-processing. The problem is matching most of them simultaneously.

For example:
1) single character entropy
2) ngram entropy
3) word repetitions and repetitions with minor changes
4) almost total lack of duplicated characters, except I and E

This is just off the top of my head.

Not many cipher types would cover all of these.