Instinctively, I want to simplify the form and make it more directly relate to the shape of two merged Middle-Welsh V forms, so that typographically there is the same parallel between that V and W as between the modern pair. That would reflect a similar outcome of a longer evolution, rather than trying to capture the ductus of the mediaeval scribal form outside of the corresponding ductus of all the other letters in such sources.
The form in BM Add. MS 36704 seems a step in this direction in terms of the lower right being comprised of a single bowl, rather than a stack of two.
When I have some time, I'll work out what the Brill options would be.
But nowadays, it is used to mean "that sloped stuff used for emphasis", and thus if sloped Hebrew or even sloped Gujarati is used for emphasis, one will push the "I" button to get it (making it a "nominal Italic font" at least)... and thus, at some point, we have to recognize that the current meaning of a word is not the same as its original meaning.
All that indicates is that the conventions of word processing software and corresponding font family are Latin-centric. HTML is better in this respect, tagging the use rather than the nominal style, and leaving it up to the style sheet to determine how e.g. emphasis or citation are displayed.
But here you are talking about the one of the roles of italic type — 'for emphasis' —, whereas I was responding to your comment that 'traditional Armenian typeface often appeared either entirely in italics', which was not, as I pointed out, italic in the sense of the roles played by 'italic'. The point is simply this: not everything that is slanted is italic, either in origin or in use.
In the case of Cyrillic, it might be noted that the italics included with many typefaces, including Times Roman, are cursive in nature, and thus do derive from Aldus and Arrighi.
Pretty much every writing system in the world has both formal and cursive modes and construction: it's one of the distinctions that emerges in any mature scribal culture. Now, in the case of Cyrillic typefaces there is, thanks to Peter the Great, a direct correspondence between several styles of in Latin and Cyrillic, but the forms of the Cyrillic курсивный are derived from handwriting in Cyrillic script. So 'cursive' Cyrillic types marry local written forms with an imported typographic style — which in the West, traces back to the Italian chancery cursive hand of the latter 15th Century —, such that it makes some sense for English speakers to call Cyrillic cursive types 'italic' in a kind of third cousin twice removed familial sense.
The traditional Armenian typeface often appeared either entirely in italics, or with the lower case in italics - slanted italics, not cursive.
No. Traditional Armenian formal text style included slanted letters. That doesn't make it italic in any sense of that word: it isn't derived from models of chancery cursive construction, it isn't performing any of the secondary differentiation or articulation roles of italic in Latin typography, and it ain't from Italy.
It makes no more sense to describe traditional slanted Armenian letters as italic than it does to describe traditional slanted Tamil letters as italic. These are distinct scripts with their own textual cultures.
Frankly, I don't think the term italic should properly be applied beyond Latin, even to related secondary styles in Cyrillic and Greek, and do so only for convenience and in context of making font families with nominal Italic fonts.
CLDR is a foundation for a lot of work in this area. But CLDR isn't always reliable in itself, because just knowing what characters are used in a language doesn't tell you, for instance, whether the form of those characters used is appropriate, or whether the font provides adequate shaping information for those characters for a particular language (e.g. appropriate conjunct forms in an Indic font).
The problem is similar to that which the 'Design languages' and 'Supported languages' in the new OT 'meta' table seeks to address. CLDR is a good first step in identifying a minimal level of language support in terms of character set coverage, but it isn't sufficient to accurately identify the level of language support beyond that, let alone the design language(s) of a font.