Can we block entire instances?

There are a couple of instances that are clearly misaligned with my values, but they're very active, so a lot of the communities keep popping up in my feed. I've been blocking the communities, but it would be pretty cool if I could just block the entire instance. I know an instance can defederate from another instance. Is there a way for an individual user to do something similar, short of spinning up an entire instance myself?