Via a John Cowan comment to this post at Stæfcræft & Vyākaraṇa, I found this essay, “Don’t Proliferate; Transliterate!” by Nick Nicholas, aka opoudjis (of Ἡλληνιστεύκοντος). It’s a fascinating look at what Unicode takes account of and what it doesn’t, what kinds of script will probably never be included (Akkadian cuneiform and Egyptian hieroglyphic) and why (“standardisation for such scripts is hard, and the people who would do the standardisation don’t need it”), how Greek epichoric scripts have been handled traditionally in various contexts (“Epichoric is Greek for ‘local’ (ἐπιχώριος), and the fact that epigraphers call local alphabets epichoric instead of local is the kind of turf practice you might expect from the industry”), and finally the issue of target transliteration script:
The choice of script to transliterate-not-proliferate into for Western scholarship was dictated by two principles: patrimony and accessibility. If you were a Slavonicist writing for other Slavonicists, or an Arabists writing for other Arabists, you would be expected to leave your Cyrillic and Arabic (or Syriac or Hebrew) untransliterated: that was the patrimony you were discussing, after all. Your target audience would be sure to already know Cyrillic and Arabic….
If on the other hand you were discussing material in a script which did not make it to print, but was present only in the original sources (accessible to the scholarly republic only with difficulty), then it was your business to transliterate it out of the original script, into a script you deemed accessible—and which corresponded to your notion of the script’s patrimony. Gothic was deemed part of the Germanic patrimony; so it was transliterated out of the long extinct and unfamiliar, Greek-like Gothic script, into the same alphabet used for Old English and Old Norse (with an addition or two). Slavicists rejected Glagolitic in favor of Cyrillic, as Glagolitic was not regarded as accessible enough, being restricted in printed use to a corner of Dalmatia….
In the late 20th century, the abandonment of Classical education means that you cannot expect a general linguist to have any fluency in reading Greek, and Greek is universally transliterated in generalist contexts (outside of traditional historical linguistics).
It’s fascinating stuff, and I urge anyone intrigued by the excerpts to go read the whole thing.