Yes, this is correct.
It’d be nice getting this in Gargoyle, too, certainly. But since there are, generally, multiple fonts in use (monospace and proportional at least, and at the extreme, Gargoyle can use 8 completely separate fonts); so how would this work when different fonts have different coverages?
On the direct topic, and related to the linked topic in the first post, I’ve been working on font substitution in Gargoyle. At least for a first cut, the best option I found is to use GNU Unifont as a fallback font, and include it with Gargoyle. This has wide coverage of Unicode (not all, as that’s impossible in a single font), and at the moment I don’t want to deal with the possibility of shipping a bunch of different fonts, such as the Noto family, to get better coverage. A single font that does fallback is better than nothing, at least! Plus I’ve added the ability for users to specify their own fallback fonts, so if they want to slot some Noto fonts in, they can. The result looks like this (sample from Zarf’s Glulx Unicode test):
Gargoyle before substitution:
Using Unifont as the fallback:
Using a user-specified Noto Serif Hebrew as a fallback:
(I conveniently cut off the part noting that the aleph is in the wrong place: that’s a future issue to deal with…)
Unifont is very utilitarian, but it does work. The more glyphs that are missing, though, the worse things get, but it shouldn’t be worse than the question marks Gargoyle currently uses.