Many scholars use the circumstances of revelation as a guide to interpret a verse. Are there specific opinions about whether this aspect is mandatory? If not, that opens a legitimate door for interpreting the verse irrespective of the (alleged) circumstances of revelation, but based on the wording of the verses as revealed. If one can substantiate that approach, refuting the claims will become far easier and more compelling.
Did the scholars say something about the use of the circumstances of revelation that can substantiate this approach?
Yes. Many of them said that knowledge of the circumstances of revelation was essential to interpreting a verse. And in some cases, it is. However, there are no such mandates in the Quran or the Sunna as far as I know. It is a flimsy argument, though, since most narrations mentioning such circumstances are not authentic.