To some degree I consider forum posts as issues. At least by trying to make sense what a post is about generally. This one strikes me with links in a thousand directions and no meat about what is expected to be discussed or cleared.
In addition to category, options are also available per topic and per tag.
So, you can be watching a category but then have specific topics on mute or normal.
Also, you can adjust the activity digest frequency. With the digest, you can still see new things in categories you are not watching. And you can obviously also just visit whenever is good and review things to whatever extent you like.
Forum topics are not issues, though they can be similar. People can have discussions here that have no implicit call for specific responses or actions (particularly in categories that are more open-ended).