I used to work for an SEO firm, I have a decent idea of best practices for this sort of thing.
BAM, I went from thousands of indexed pages to about 100
See screenshot:
https://x.com/donatj/status/1937600287826460852
It's been six months and never recovered. If I were a business I would be absolutely furious. As it stands this is a tool I largely built for myself so I'm not too bothered but I don't know what's going on with Google being so fickle.
Updated screenshots;