I really like the idea and would like to see further discussion!
I've explicitly used "Puzzler1" in titles a few times, and I think that only a fraction of the time did I have some idea of the answer, so I'd like to see a distinction between the discussion of questions for which the OP knows the answer (which I think is a different issue entirely2) and the discussion of questions which might warrant a "puzzler" tag.
The questions Have any knots been tied incorrectly on a spacecraft? and What was the first piece of wood to reach the far side of the Moon? Or the first spacecraft? have received +4/-3 and +5/-5 votes (currently) so it's possible that "Space Trivia" might not be a good tag, or at least need to be tabled. It might be hard to define or scope that to avoid absurdities.
My personal belief is that this site's user community is capable of curating, maintaining and sustaining a Puzzler question tag, as long as it had a well defined tag wiki and associated meta post that scoped it carefully so that poorly crafted questions with the tag could be quickly and unceremoniously closed.
1in reference to and homage of the Car Guys' weekly Puzzler (the Puzzler website), which was often science or physics-based as the Magliozzi brothers were in Cambridge, MA and both had degrees from MIT.
2in general there's no problem with asking questions in SE for which the OP knows the answer if asked for the purpose of generating helpful or interesting answers rather than "look how clever I am" type motives.