What do you think about enabling enabling “Allow topic owner and staff to mark a reply as the solution” feature in Support category? It would allow highlighting an answer as solution and topics that have a solution would be marked with a checkmark in the topic list - see in Developer category.
It would be helpful to easily see which topics are answered and where further help is needed. But at the same time, there may be multiple good answers and the topic owner may not take the time to set an answer as solution (and sometimes it’s just too hard to provide a good solution).
We could also close topics that don’t require follow-up anymore (either answered or nobody) - either manually or using auto-close feature (topic closed after a certain time after the last answer). These topics appear with a padlock icon (see the “Error uploading…” topic in developer category for an example).
We could do both - resolved if there is a chosen solution and auto-close after N days of inactivity.