be closed for adding after a certain time frame of not being touched (3 month or something like this)? Or give a user a message, if he replies to such a long time untouched thread at least.
I see the trend, that users add their own question to threads, which have not been touched for more than a year, are marked as answered, may not be related to the current status of the product and are difficult to follow up due to their length.
Best greetings from Germany
Olaf