We also have
These plugins both let you disguise your identity as a staff member. i.e. you can make a post from a more ‘official’ looking account, which cannot be obviously linked back to you as an individual.
However, I don’t think that’s quite what you’re asking for? You want a way to make Discourse look/feel like it does for regular users, and then “enter sudo mode” to make all the extra admin-only functionality available?
I think it would probably be quite hard to implement… but it would be pretty awesome! Many years ago (before I joined the team), I made this component for my own self-hosted forum. It has the same kind of idea (make regular/admin privileges obvious), but it’s limited to one very specific case:
If there are other tightly-scoped cases that are often confusing on your site, it might be possible to make similar theme components to popup warnings before taking admin-only actions.