Even with detailed 404 setting enabled, following a category page (site.com/c/category or site.com/c/category/subcategory) does not link for a custom 404 page, the same way clicking on a post page (site.com/t/title/1234) does. Or am I missing something ?
Is this the intended behaviour ?
IMHO, the custom page for the category/subcategory is even more important than for the post (there is less risk to acknowledge the existence of the category than the post, plus the custom page would link directly to the group in question). So i would suggest to add the custom page for these links as well.
Possibly – @eviltrout can you have someone estimate effort on this one? I’m sympathetic because categories are closely tied to permissions in Discourse, so it makes sense that the 404 would reveal a bit more in this case.