Voynichese is a numeric cipher?

[oshfdk]

Your question contains an as-yet-unproven assumption, namely that the cipher must be quick to read.

This whole thread contains an unproven assumption that Voynichese is a cipher. No-one has proven this so far, still we can have good discussions about plausibilities and hypotheticals. I never said in my post that Voynichese "must be" quick to read, I just said this would be practical.

Since, if it is a cipher, it is almost certainly a complex one (otherwise it would have been cracked already), it would always take some time to decipher it.

Not true in general for ciphers, for example, a simple grille cipher would be hard to decode, but reading it is a breeze - you just put the stencil over the text and read it. Hard to break doesn't imply hard to decode once the cipher it known.

There’s no reason to assume that it has to be quick to read, especially if it involved knowledge that was dangerous at the time. In this case, the main concern was preventing it from being decrypted in order to protect one’s life. The time it took to decrypt it likely played a lesser role.

Making it easy to read makes a lot of sense for a book. It's not a single use message, books are used over and over. Books often contain cross-references. Making an enciphered book hard to decode actually makes it more dangerous, because it forces the readers/users to make notes and leave a paper trail of partial decoding attempts that an adversary can use to break the cipher. A cipher that can be read off the page (but very hard to break) is much more practical for a book.

Generally, once we start talking about Voynichese as a cipher, we are already in the realm of conjectures and assumptions. And until we have some deciphering, the arguments from practicality are as good as any other.