Shared-private sounds like what's really needed and useful.

Personal-private sounds like scope-creep - the mentioned examples (many of which I would classify as "application configuration") should arguably not be solved by AT but by each app. While common solutions, patterns and libraries are useful, they can live outside normative AT specs. And for the actually valid use-cases, aren't those just a special case of private-shared with an audience of one? Doesn't seem warranted with a separate flow for that special case.