you need to think more abstractly about what a person might want to be notified about

an issue is a post, that is tied to an event that you created the root of, it tags the event and thus you would set up a filter that looks for events that tag roots (repos) that you want to monitor, and possibly, not ones of people you have muted

and mutes, they are so broad, you may not want to read someone's war and peace posts on demand in your issues but usually enjoy their long form posts, for example

so, notification engines need to be complex by nature, highly configurable, with sensible defaults that don't give you notification fatigue too quickly... and temporary ignores that can quickly be set up when you need to focus, generally, or just not see some particular thing