Oh, it works consistently, but it is a hassle to add the url.
As long as the tags are selected by the devs and not by the players, I doubt that any filtering will be implemented officially. Look at steam, there you could filter tags if you want. But you can also suggest tags for a title, so the accuracy of the tags is higher.
Also you can enter tags that are not in the list in the tag search box. How would "runs on retro hardware" tag look like?
Something like this? https://itch.io/games/tag-commodore-64