I've said this before, but this is a good opportunity to say it again.
Especially with the exhibition gallery, I don't agree with the (relatively new) policy of automatically closing threads. The items in there are not necessarily only of short term interest and people may come back years later with comments or suggestions.
Some of the projects I have put in there have taken several months to develop and document so hopefully these are also of interest to other users and may even add some value to the site or even more generally to the Arduino Ecosystem.
I quite like it when users respond some how to indicate they have found these contributions useful or event built a project based on such a design.
So, I find the arguments that these attract "me too" posts or pose a risk for spam posts as somewhat spurious and I believe that risk is worth taking even if it involves some moderator intervention from time to time.
Yes, I know that someone can always ask for a thread to be re-opened but the process of doing so would tend to inhibit otherwise welcomed comments. Some such comments land in my personal message box, once the thread is closed, so I could also ask for the thread to be reopened, then copy the users comment into the thread as a new post and direct him/her there to continue as required, but it just add to the complexity of it all.
Yes, I also know that there are more appropriate sites for posting projects (github etc.) but I'd have thought that , especially with the site going in the direction of a social media collaboration platform with all sorts of tricks to encourage participation and content creation (the plethora of badges, likes and other knick knacks) that automatic closing of threads was contrary to that philosophy.
Just my opinion, of course.