Tbf that doesn’t actually do much at all in terms of blocking an instance, hence is horribly misnamed imho. All it does is mute communities located on that instance. The users from that instance can still harass you in posts in other communities, triggering notifications, vote on your content, etc.

The Sync and Connect can do true user-level blocking of any instance you choose without needing admin support, and the Lemmy alternative PieFed, or e.g. Lemmy.cafe or dubvee org have blocked all of the big 3 tankie instances.