Why not positional variation?

[RobGea]

For example, we could try assuming positional variation to convert Voynichese to something like Roman numerals, but then what?

Codebook indices would be one way to use numbers.

And once you have numbers you can subject them to mathematical operations where the resultant number does have meaning, like in Greek Isopsephy or Hebrew Gematria.

i recently cooked up a method to convert plaintext and eva to numbers, then convert between them. -- didnt work well though, entropy too high, words too long.