This isn't a question about why are there chapter headings, should there be chapter headings, what is the history of chapter headings, or "are chapter headings a sort of iota?"
https://en.wikipedia.org/wiki/Chapters_and_verses_of_the_Bible#Christian_versions
On those topics, the information on wikipedia has seemed ample to my needs (although the part I need them from has very few references, and any book recommendations are hugely appreciated)
The question is what tests or methods does Biblical Hermeneutics apply to chapter headings in the translations and editions that admit of them, and with particular regard to how they should be worded?
With the best will in the world, one can see that testing might not have historically-actually taken place, and that (for argument's sake) a centuries-old tradition of titling Mark 5 as "Jesus Restores a Demon-Possessed Man" (NIV) or "Jesus Heals a Man with a Demon" (ESV) might struggle to be overturned by a hermeneutic objection that it spoils the surprise in Mark 5:15 (which is the first time the Greek term δαίμων appears).
It might do to discuss this example, but without descending into a Word Study of what δαίμων or πνεύματα τὰ ἀκάθαρτα signify. Or indicate. Or say. Or mean. Etc.
My approach would be that if this contention was made, and didn't stand, then it should be recorded that it didn't stand (and why and in what forms), which I hope is approaching the spirit of "show your workings"
And it might be interesting to know a little of how publishers and presses do go about this in the real world. One can easily imagine traditions in which a proposed chapter-heading is carried down stone corridors, and recited, and then blessed in triplicate, and others where it is brainstormed - but also there may be specific inventions of benefit to exegesis and translation generally. It can happen that scribes' and scholiasts' notes and chapter headings have sometimes become mistaken for a text, and would hazard that in our modern age we have invented little that makes the readers of future millennia more proof against these mistakes than we have been.
Perhaps does copyright apply? With some horror one imagines publishers jealously guarding the precise wording of their chapter headers, and mentally counting each time they find someone unwittingly pasting them to the internet.
I beg leave to exclude the Psalms or any points in the scripture where sometimes it is controversial whether in antiquity something like headings may have become part of the scripture their having been inspired. Well, there might be valuable points to be drawn from the techniques applied in such situations, and those who know of them will know how to describe that in a respectful and collegiate way.
When the marketing team wants a gloss for "John the Baptist Beheaded", what sorts of things does the exegete ask of the text? And the heading.
EDIT (08/08/2024) Thinking further on the understanding of chapter headings as just interpretation. What is (currently) done versus these?:-
Headings steering the reading e.g. Mk.12:28 "Jesus' theory of ethics"
Headings being longer than the passages
Headings that future readers/scribes/optical recognizers of characters/machines-for-large-languages/etc might blend with the text. e.g. if they read some edition of NIV as You are badly mistaken about the Greatest Commandment
