Firstly, thanks to all who tried to help! I thought I’d update everyone…
Actually, I forgot to mention why this was important to me and what I was trying to achieve. I understood that I’d be able to rearrange the order of posts easily - without having to resort to dates if I enabled ‘Folder Numeric Prefix’ - The thing was that my theme which was based on Bootstrap4 then showed these child pages within a dropdown*. I wanted a single navigation link that landed on a page that then showed blog post summaries, linking through to blog posts (child pages) in a defined order - which was creation date, rather than modification date.
(*Actually, I had to enable dropdowns for navigation elements in the theme configuration, because I needed more than one.)
To ‘solve’ my issue I finally had to cheat a bit… I manually added a static link into navigation which linked to a new parent page that had the child pages I needed and this parent page had ‘Folder Numeric Prefixes’ - So each of the child pages could be ordered as desired.
The down-side to this is that the manually added link has to be after the dynamic navigation - so always the last link in the navigation, but until I can figure out a way to alleviate that, this will have to do.
I attempted to get the user to define a ‘published on’ date when creating the blog posts, using a blueprint to store the value in frontmatter, but had no luck in being able to sort by that value anyway… I’m retrieving values from frontmatter for use by twig in other places - it just seemed to be unhappy to sort by dateTime values for me.
This is really just to record the things I ran into issues with, and how I managed to side-step around them, in case anyone else finds themselves stumped trying to do something similar in the future. I’ve read so many posts here where users ask something and then don’t report back, which really isn’t that helpful. I mean, did they find an answer, give up, are they still trying… etc? I would have asked, but lots of posts are several years old, so I assume they’d either worked it out or given up.
Anyway,… There you go.