Yes I see that as soon as you add CatalogContentType to any extending class it errors.
I've always tended to build the site settings as a separate assets area for all settings across including commerce with a node for each grouping so that's an approach I'd suggest rather than trying to add them to the catalog.
My requirement is to add some properties inside the Catalog. Such as Meta tag related properties inside the catalog. So, the editors will be able to change the meta tags in Catalog.
I have tried to do this by defining a content type as mentioned in here by extending the CatalogContent. But the CatalogContent could not be inherited as mentioned in the documentation.
So I am wondering how can I add properties to Catalog which will be displayed in the Commerce edit view for Catalog content. Any input on this is appreciated. :)
Note: A similar question is asked in 2018. But it does not mention a way to add properties inside the Catalog itself (It mentioned a workaround to this by storing the additional properties elsewhere. But I need to include those properties inside the Catalog. So, editors could browse the relevant catalog and add content).