I noticed responding to posts in communities hosted at lemmy.ml gives the following warning:
This post is hosted on lemmy.ml which will ban you for saying anything negative about China, Russia or Putin. Tread carefully.
While I see where this is coming from and I agree with the general sentiment, I'm not sure it's a great idea to include such a message. I basically read it as an invitation to be off-topic and to derail conversations in order to annoy the admins. While it comes from a point of good intentions, it can be disheartening for the people running communities on Lemmy.ml to receive comments about Russia from users basically trying to get banned, in communities that has nothing to do with this issue.
It's unfortunate, but a lot of valuable older communities are still hosted on lemmy.ml, and I think PieFed users should be encouraged to be constructive and on-topic users there as they should be everywhere else.
An alternative suggestion: Maybe it could be useful to remind people which community they are posting in? Like, "This community is dedicated to renewable energy. Please keep this in mind when contributing to the discussion". Then again, that would be a mess to implement in a good way.
An idea that has been spinning in my head a bit is to allow people to subscribe to different levels of moderation. Basically allowing users to choose a "curated", "moderate", or "liberal" experience.
Curated: Whitelist of servers rather than blacklist. Well-moderated instances only.
Moderate: Blacklist rather than whitelist, but blocking annoying instances like Lemmygrad and Hexbear. Aiming at a wide yet enjoyable experience.
Liberal: Blacklist, but only blocking instances that allow (or are incapable of handling) content that goes against the content policy.
It's probably more difficult to implement than what it's worth. What I like about it however is that it would make the whole process of content curation much more transparent. Right now it's often not so clear to people signing up to an instance what kind of moderation policy they will be signing up for. At least this would allow the user some agency even after sign-up.