YMMV is for items that are reactions of the audience to works and tropes that need a significant judgment call to tell whether they exist objectively or not.
Should these items become members of YMMV?
Note: Audience Reactions need to be subjective, emotional responses and things that are likely to cause arguments and disagreements. Merely being outside a work or inside an audience don't make things YMMV
This issue has been resolved and voting is closed.