Hi @Simon_Collingridge And welcome to the community!
Sadly i don’t have the answer you were looking for, but i can suggest a different approach that you can use to be able to get the most out of automation.
I’ve never used pages and subpages as you are using them because after maybe 10 main pages the concept of the menu is somehow lost, and it becomes hard to navigate in a doc (but that’s just my personal way of using coda, the best part of it and of this community is that there is not one way of doing things and coda is always evolving to improve the number of possible use cases, so this is just a suggestion based on how things are now)
If you organize content in a table, with relatives parent category and sub category (or sub-sub-sub category, possibilities are more or less unlimited), and you filter them according to the page you are in, you obtain the same result but having them as rows allows automation to work on them.
And to get the same “UX” you can use buttons or dropdowns or other type of user interactions
I’m 100% sure that you find yourself well with your current setup and translating all your KB into a table is not a 5 minutes work, but at the end you should obtain a much more elastic and dynamic content manager!
If you want to further discuss this possible setup i’m here and we can think together of a pretty way of managing them, but we can also wait some insight of someone else that have built something similiar
Have a nice day,