Finally wrote up that proposed policy page on best practices for Tabs and Tabber. If there are any other extensions where we need to use them in specific ways for formatting reasons, I would not be averse to making a mega-page covering them and would be happy to solicit advice:
https://allthetropes.org/wiki/Blog:Tabs_...e_Proposal
https://allthetropes.org/wiki/Blog:Tabs_...e_Proposal