Just discovered that while Mona does not enable me to block instances, Tusker does. So I switched over to that to block an extremely annoying instance that generates hashtag spam via bot accounts. I've reported these accounts and the instance multiple times but no one seems interested in doing anything about it. The Block feature is amazingly powerful to keep crap out of your feed.
Hey, @andypiper, any idea if there's a fediverse-wide policy about hashtag spam?