I've created an experimental branch in a fork to see if we can check for updates on an automated basis using GH actions. This doesn't use the comparison functionality you wrote but rather relies on git to track changes for us. For this reason, I save the Excel as CSV, so git can generate diffs etc. In addition, it uses csv-diff to generate nice commit messages that summarize what has changed.

The slightly annoying thing is that I now have to wait for actual updates before I know if it works. So consider it an experiment for now, but I thought you'd like to know :-)