Geoffrey, (all); I think you’re moving the goalpost of the original intent of the authors of he fallacy. The question is whether the person using the appeal is providing a suggestion that should be considered, or whether that person is claiming such an appeal provides decidability (must). If the latter it’s an appeal to authority.
That said your disambiguation of expertise from authority is excellent.
This category of question is common in philosophy, with the most famous being ‘free will’, whose authors were demonstrating that humans have the agency to take responsibility for the morality of their words and deeds.
It says nothing about the limits of human cognitive agency.
Cheers. 😉
Reply addressees: @primalpoly