Yet how much do you know about chocolate?
I feel like there's a missing comma.
- Yet, how much do you know about chocolate?
- And yet, how much do you know about chocolate?
- But how much do you know about chocolate?
- But, how much do you know about chocolate?
These are all acceptable to me.
I think 'yet' as a conjunction can always be replaced with 'but'.
'Yet' as an adverb with a meaning like まだ・もう of course, cannot be replaced with 'but'.
E.g.,
- The building has not yet been completed.
- That is an as yet unsolved mystery.
'But' as a conjunction cannot always be replaced with 'yet'.
If it is calling attention to a contrast or asking the listener to pause to consider, the replacement is fine.
Sharp contradictions cannot be replaced with 'yet'.
- You might think so. But, no. The truth is otherwise.
If you rephrase more softly you can communicate essentially the same meaning with 'yet'.
- You might think so. Yet there is evidence that the truth is otherwise.