Ben, thank you for the detailed insights into your logic.

I wish you well with Serif's Affinity suite. Having reasonable understood your objective, I would never have chosen Serif or Xara as a repository.

Your MSA database is an abstract and keyword indexer that leads to a two-step search for a phrase in an actual document.
It does provide a form of digital asset management (DAM) that allows you to link in external assets. By external, I include local filestore as well as Internet.

I would actually develop your Zettelkasten system slightly. Change the date to yyyymmdd. This immediately affords a date order in MS Windows. The ddd abbreviated Month forces an alphanumeric sort that jumbles the months.
CamelCase is good but I would go a step further and include some keywords into the filename. MS W7 accommodates 260 bytes for the full path length. W10 NTFS can be as much as 32,767 bytes.
yyyymmdd-ThisIsAnExceedinglylongFileName-Keyword1-Keyword2-Keyword3.txt

Using this approach, I can use 'Everything' to quickly locate a filename through fragments of words: 'his ord2 word3' catches the above filename and highlight the found fragments in no time: I have 3M files stored locally and I can type in 202403 as fast as I can and I get 604 hits.
Using Obsidian, which comes with its own Search engine, the retrieval is more sedate (way faster than MS Windows), but here, you are searching all content and filenames.
Saving a Search as a Bookmark returns results extremely fast.

Archival storage under W7 is your main problem. At some time your W7 machines will die and your archive and legacy programs will disappear.

I took your https://www.benwiens.com/transportation2.html page and quickly converted it to MarkDown for use in Obsidian.
I renamed it 20230305-UrbanTravelIssues.md.
I added in the keywords as Tags.
I added in all the associated images as adjunct files.
===
I searched for a range of terms and all worked perfectly.
I opened up the Links window and picking any of the images, I could fire it up into its native editor, alter and save it and it immediately updated the principal document.

So provided you have a text editor and a image editor, you could even throw away Obsidian & MSA and still future-proof your active and legacy documentation.

Acorn