I think that our current wording is too specific, and as a result it cannot be applied with confidence to a significant number of questions that have little value to future readers. As a result such questions can remain unanswered for many years, with little hope of attracting an answer in the future.
The class of question that I am thinking of is the one where a user describes some symptoms of a problem, without being able to also describe a procedure to reproduce those symptoms. Such questions sometimes attract support via comments by other people who say that they have seen the same thing, but they too are unable to describe precisely what they did. As potential answerers we are left with two or more descriptions of the same or similar symptoms that may or may not be due to the same cause, and for which a more detailed procedure may or may not be forthcoming from those who say that they have experienced it.
These are classic non-reproducible problems and for anyone not familiar with the term non-reproducible in a software problem solving context, it means not having a procedure that can be followed to demonstrate the symptoms of a problem at will, and not that the same or similar symptoms have simply been reported by more than one person.
If we were a GIS Software Support Site, then I think we would have an obligation to keep such reports open until the symptoms are better classified and hopefully resolved, but we are not a GIS Software Support Site, and so I think it would assist our volunteer answerers to maintain enthusiasm if there were a tool like this to close some questions which they have little hope of answering, and which may have been asked by a user no longer active on the site to assist with further clarifications.
The wording that I propose for this custom close reason (which has 8 characters to spare) is:
This problem cannot or can no longer be reproduced.
Changes to the system or to the asker's circumstances may
have rendered the question obsolete, or the question
does not include a procedure to enable potential
answerers to reproduce the same symptoms.
Such questions are off-topic as they are unlikely to help future
readers, but editing them to include more details can lead to re-opening.
I hope people will not be unduly concerned by the thought of this close reason being used to close more questions than it currently does, and will appreciate that the mechanism to re-open a question is already there for those cases where anyone may use it (or any close reason) overzealously. I suspect that this close reason will continue to be used in a "close later" rather than "close early" fashion.