This question was closed with three votes for "insufficient research" - although I'm unclear why, because even after doing all the "research" suggested in the answers, the correct answer is still not obvious to me. It was then reopened with three reopen votes. And then re-closed with three new close votes - again on the grounds of "insufficient research", but again with no further details given.
Since a question that has been closed and re-opened is plausibly on-topic for this site (given the successful vote to reopen), should there perhaps be an increasing number of close votes required to re-close a question that has previously been reopened? Or perhaps a reason should be required for re-closing, and a moderator would need to approve it?
I think that this community should err on the side of inclusion for questions that are borderline on-topic (even putting aside questions like the one above, which I personally think is clearly on-topic).