From the new easydiscuss Alpha updates, easydiscuss is aiming to replace support ticket systems, and I think something like what I am mentioning below should be considered
So, in a "Question answer" type of forum, user posts question, and support answers it. Neglecting the fact that other users might try to engage, I would love to see something like this screenshot -https://i.imgur.com/5rhiDiq.png
Basically, its like, a user asks question. Support answers it. Now, user is not shown reply option. Instead, he is shown two buttons "Accept as solution" and "No, this didnt solve my issue". If the second button is pressed, the reply box shows up. If accept as solution is pressed, the support reply is marked as answer, and ticket is marked as solved :d This has two advantages, firstly tickets are automatically marked as solved, and the "marked as right answer" automatically comes to the top, so if someone has the same query, he would find the answer more easily if he searches for the same question.
Now, depending on category, you might allow discussions even after thread has got an answer, or lock the thread and no longer accept replies