On the subject of adjusting how threads work, and their life cycle specifically, here is one thing I have often thought: Get rid of the 'SOLVED' thing.
If there is one thing that I do think UA does well, that I've always agreed upon strongly, it's that specific thing. I won't rant on and on about the principles of it too much, but suffice it to say that there are 2 opposing reasons, in order of importance: 1) The user who asked the question should not be thought of as an authority as to when the thread is "solved"--they don't know enough [at least, not enough precisely about the thing they had the question on]--in order to do so. Accepting this flow would be like a student grading their papers. 2) Better to consider the thread as a forever-open topic...That is, who is to say that the solutions presented aren't inferior to anything that might be presented later on? This concept of infinitely-improvable design is a fundamental aspect of "developer maturity". 3) It wrongly discourages additional feedback/research/solutions that may come later...And again, worse yet, it allows for the most inappropriate decision-maker as to when to "cut off" additional inputs.
Allowing the person who posted the question to decide when the feedback presented has "solved" the case goes against the principle of always being open to better design. And, IMO, one of the biggest things that most less experienced developers need to learn is to allow feedback to dig deep & wide...Do not just take the first thing that "works", which is akin to the old comedic saying, "Hey, it compiles! Ship it!" ... Which newer developers are generally awful about, until they learn differently.
Just one man's humble opinion. And I grant that this is more philosophical than it probably is practically consequential.