Robert Holmes villainidea - when you block someone, you can type an optional reason, visible only to you in your Blocked Users page. this way, you can easily remember malevolents ('called me a slur' 'climate change denier') and sort them from good but temporarily annoying people ('not interested in their Discourse thread on day when I had bad family news')
hotwheelsmaster69@fireh9lly sounds like a great idea; would also like temporary, time released blocks for the second part of your suggestion. That kind of stuff is often random people on the public timeline that I'll forget about and forget to unblock later.