All text has been converted into alphabetic characters.

[Maruyama Toru]

[..]
In VAM, the character forms found in the original texts are mapped to the widely used Latin alphabet so that they can be processed by computer. This does not imply that the language of the manuscripts is Latin.

Understood.
The most languages using Latin alphabet are not Latin.
But for many languages, Latin alphabet is insufficient to transport all details, so they added several extra symbols during the centuries.
And those extra characters are only the things that can be seen clearly; in my language (German) are at least 3 different understandings of -ch-, but it is written only -ch- in all texts. German Th- is not English Th-, etc.

How will you see what is modeled in VMS in case the source language was never related or is hardly compatible to Latin?
How can you get something working with a reduced set of 14 characters?
Why don't you just use some existing transliteration and transcribe it to your VAM?

I think there is a difference between representing a language and representing the original glyphs.

VAM is not intended to represent pronunciation or to reconstruct the source language. It is a direct mapping of the original glyph shapes into a computer-readable form.

The current version of VAM uses 16 characters, not 14.

I have no idea how the original glyphs were pronounced. I have not assigned any sounds to the VAM characters. My mapping is based entirely on the visual shapes of the original glyphs.
Therefore, it does not matter whether the source language is compatible with the Latin alphabet. I am not assuming that the manuscript represents a language that can be written in Latin characters.

The purpose is to preserve the original glyph structure as directly as possible, so that I can investigate what the manuscript may be modeling.

This is also why I do not simply convert an existing transcription into VAM. That would mean starting from someone else's interpretation of the glyphs, rather than examining the original forms directly.

I have not assigned sounds to the VAM characters. VAM is a visual mapping system, not a phonetic transcription. I want to examine the structure and relationships of the original glyphs first, without assuming what sounds they represent.