Hello @techmagus this looks really cool.
I had the same problem and ended up with this post : manage-easily-any-seo-schema-org-thru-your-different-sites. I created a private generic theme.
Main difference I can see is as I’m a really lazy person, I do not like to write twice the informations. So I choose not to use a dedicated .toml and reuse .params .
Do you think (are you interested in) we can merge our 2 theme/module to get best of both worlds ?
Any thoughts ?