Is the Voynich illegible?

[pfeaster]

That seems to me like a very attractive way of thinking about Voynichese. Would I be right to deduce that for this system, you would go as far as not differentiating at all between EVA [e] and [i]? So the only information conveyed by the glyphs we are talking about is the number of marks and the connection of the flourish?

I guess that would take this line of speculation to its logical extreme -- maybe as the "strong" version of a hypothesis that also has a "weak" version.  There are certainly contexts in which [e] or [i] is much more probable, but the same could be said of, say, [ſ] versus [s] in early modern print, so perhaps that's not a decisive counterargument.  There do seem to be cases in which differently shaped hatchmarks seem to be written so as to contrast purposefully with each other, e.g., any vord containing [eai].  But maybe the salient point is the contrast itself -- much as either \\\\// or ////\\ could indicate "4,2" as opposed to just "6," even if \ and / "mean" the same thing.
 
For what it's worth, it does seem as though any system of Voynichese that required the reader to be able to distinguish clearly by eye between [e] and [i] should often have failed in practice -- and that somehow feels important.