First of all, I’m hugely grateful that you took the time to work your way all the way through this. In retrospect, it is obvious that I should have done more testing myself before asking for help.
Regarding the text entry, this is done using standard macOS text fields, so setting Verbosity > Text > While typing speak > Characters in the VoiceOver utility seems to work for me.
As an aside, it also seems to me that setting Verbosity > Speech > Text Area to “Custom” and unchecking “Content” in the VoiceOver utility somewhat helps with “the silent VoiceOver output quirk,” but I haven’t tested this enough to be sure.
I just thought it was a bit strange since it was working fine when Tag had to speak Elvish earlier in the game. Oh well, probably one of VoiceOver’s random foibles. In either case, it looks like Journey is fully playable in Spatterlight, which is very impressive since it’s essentially a point-and-click!
I’d love to test this, but I no longer have a Mac, unfortunately. If anyone can ever get Gargoyle to an accessible state and make the same changes, then I’d be glad to test it. Another Infocom game you might want to look into is Bureaucracy, as the opening form has been inaccessible for years, and if memory serves, Seastalker also has a section of the game that isn’t fully accessible either, but the easiest way to fix those would be to change them at the source code level and release screen reader friendly versions. Journey, on the other hand, is more CRPG than IF, so there’s not a lot that could be done for it, meaning it has to be made accessible from the interpreter side.
Unfortunately, the way Spatterlight makes Journey accessible is pretty Mac-specific and non-portable, and the same goes for Bureaucracy. Hopefully it might inspire someone to implement something similar in a more cross-platform friendly way.