Hi Phil, thanks for sharing. This looks very promising!
I have a suggestion for an additional feature which might already be available, but I might have overlooked it when going through the Google doc and the PR: A way to promote the Bounding Box would be to populate these fields based on the selected value in the Country field. So far, this has actually been the most common use case I have been dealing with when it comes to geospatial metadata: A depositor has selected a country, let's say Norway or Sweden, and I want to add the coordinates to the Bounding Box. I guess for most countries one could use a look-up service to generate these coordinates and then add them to metadata record?
Best, Philipp