Another feature that would make sense related to this:
If tag filter is enabled, yet only certain categories have tags availble using the ‘Tags that can only be used in this category’ in category settings, I believe the homepage (both the main category, latest and top) pages should have the tag filter disabled by default.
I.e. only when digging down into the categories/sub-categories with tags allowed should the tag filter be shown (showing the respective tags available).
Otherwise from the homepage (whether that be categories or latest), you’ll get a whole bunch of tags in the filter, often without context as they only have context when filtered inside their respective categories.
Does this make sense?