I think to cover this in interface settings, we can remove our existing setting “Show original content instead of translated content.” and replace it with a multiple choice section for “content language” (separate from “interface language”)
The default here would be “translate all content”
Other options would be “Do not translate any content” and if someone chooses “exclude some languages from translation” we can then show an input that allows languages to be added to the list of exclusions:
I think this would help solve the initial issue of avoiding translating all content for the people who want a selection. We can also consider more ways to surface this to make it more discoverable so it’s not only buried in user preferences, if needed.