A (somewhat common?) point that is made by Primarily-Opinion-Based close-voters is that we can close questions that we think have never been addressed, and simply reopen them when someone does come up with something. For example, this comment:
I'm reasonably sure there's no canon answer. If I'm wrong, you can always ping me and the question can be reopened with trivial ease
As such I would like to request that the question Would it have been possible to trap Lord Voldemort in Professor Quirrell's body? be reopened, as I would like to post a non-opinion-based answer.
A recent Reopen Review failed to reopen the question, but if the above is true then the question should be reopened in response to someone stating that he/she has an answer to post.
(Disclaimer: I make no claims that my answer is the correct answer, nor even that it entirely answers the question. However, it is solely based on facts from the books, and provides relevant information, which qualify it as an "answer". Moreover, there are two existing answers which do not contain this information, which may therefore give readers a skewed view of the subject.)