Is the Voynich illegible?

[Mark Knowles]

A much greater problem in my opinion is that certain characters exist on a continuum, notably a-o, s-r.

This is certainly a problem. In the example I referred to on the Rosettes folio with EVA-asal or EVA-osal or maybe even EVA-aral/EVA-oral possibly representing the word "Asia". If that word association is correct then one still ends up with a poor crib word as we do not have a clear correspondence between word and specific well-defined Voynichese characters. With illegible words like this, one needs a much larger crib than with legible words to hope to make any progress deciphering Voynichese as one has to take into account many different possible Voynichese mappings in one's crib.