TL;DR: I have made a python code that will index your JD hierarchy for you.
You can see/download the code here: GitHub - drillvoice/psychic-succotash: Python code to index 3 levels of folder hierarchy. To run it you will need Python.
I have begun learning Python and today I had an experiment at using ChatGPT to develop Python code. One thing I want to do was index my folders that use Johny Decimal. After a few rounds of iteration I’ve got something I’m happy with. It will index 3 level of JD Folders (and there should be only 3 levels!) and output an index.txt file in the top-level folder. You need to copy the path for top-level folder and paste it when prompted. This was mostly ChatGPT doing the work with me tweaking it to get what I wanted.