Is there a way to see an overview of which categories have Solved enabled?

If Solved is enabled per-category, is there a way to quickly check all categories to see which ones it’s enabled on?

I don’t think this is possible through the UI, though you could pull this information out using a data explorer query. Something like this perhaps:

SELECT ccf.category_id
FROM category_custom_fields ccf
  JOIN categories c ON = ccf.category_id
WHERE = 'enable_accepted_answers'
  AND ccf.value = 'true'
ORDER BY c.position ASC