This small userscipt for tampermonkey adds some additional tag groups under the rating tag selection. These are buttons which, for the most part, are fetched from getting implications from the api.
Currently it adds groups for art type, and common explicit tags. Tag groups are only visible when you click a rating which the tag can apply to.
It's relatively simple to add new groups yourself if you really want to, you will require extreme basic javascript knowledge, and there is an explanation in a comment of how to do that here
Here's a slightly outdated example video, and the full source code: https://gist.github.com/DontTalkToMeThx/74a4a271e19cbe14195cd2c6671736ba#file-readme-md
Download guide:
1. Download tampermonkey for whatever browser you're using.
2. Click here
3. Click install
Note
Sub groups take time to load, and will only pop up after being fully loaded, this is why when you click a tag, a second or so later a new group will pop up.
If you click your rating too fast the initial groups may not be loaded, these aren't auto updated, so you will need to click a different rating and click back to load them. At most you should have to wait 2-5 seconds, depending on your computer and internet.
This was made due to this feature request. However, it does not replace the feature request. Getting something like this on the site without a script could massively enhance post tag quality.
Let me know if you have any issues, or any feedback.
Updated