hemlockiv I feel like your response here is a little out of line. Here you say that you also didn't look at the code:
hemlockiv I haven't looked at the AOSP code behind Private Space, but the code in the original shared gist may even be possible to tweak to create multiple Private Spaces. Thoughts?
So if both you and ryrona haven't looked at the code, either one of you could be right, or the difficulty in implementing multiple private spaces would be something in the middle, or a medium difficulty thing. Regardless, it doesn't seem appropriate to disagree with someone's guess so forcefully when you're also guessing.
As you mentioned, the gist that you shared works with Island. You can try yourself to see if it works with private spaces (hopefully) next week after Android 15 is released and report back here. I kind of doubt it'll work the same way, but it might work. I don't know if the developers will decide to take the time to figure out how to support multiple private spaces, but if some community members figure it out and make it easier for the developers, then I'd say the chances could be higher they add something to GrapheneOS (though don't take me saying that as a guarantee, I'm just a moderator, not a decision maker, so I'm just guessing myself here).