Future updates to Lemmy already plan to include labels for communities iirc, although I am not sure about if instance labels would be included at first or not. And even if those are applied by instance admins, for maximum friendliness it seems like it would be good to reach out to the very communities that they apply to while making those labels. e.g. going from lemm.ee to Hexbear could perhaps say "come here if you aren't afraid to get dunked on and we will argue deep points together, though be warned that people indoctrinated by Western socioeconomic capitalistic thought processes may be in for quite a difference of opinion!". Lemmy.ml could be "we support older-style Marxist–Leninist thinking, but note that we strongly enjoy making fun of the West, so beware ye who enter here - we will educate you properly!"

Instead, visiting Lemmy.ml says "A community of privacy and FOSS enthusiasts, run by Lemmy’s developers", followed by a link to "What is Lemmy.ml" which as you can see is broken, pointing to a post that appears to no longer exist.

Perhaps this is all hopelessly naive - but it could be tried before abandoning it? I have been known to throw a jab or three at the expense of my own home Western nation (USA) - though it definitely comes across differently when done externally, and also by people who very much seem to not be joking when they talk about literally murdering people. (I mean, I am aware that that never happens in Russia or China, where someone can fall out of a window, then shoot themselves in the back of the head, then fall down a flight of stairs, then shoot themselves in the back of the head again, then fall down another set of stairs, and finally out of a second window... but in any case, this vehemence seems directed at the peoples in the Western nations, and regardless of its degree of truthosity - a word I made up entirely just now but wish that I could use from now:-D - it scares away the normies for sure.)

Anyway there are only so many instances, and only so many communities, and most do not need such a warning, or possibly the instance ones could be automated as applying to all communities on that instance. So it's very doable. As compared to now where it is full federation vs. full defederation, offering literally nothing in-between (unless you have an app that can implement a block of all comments from users on a specified instance).

Btw PieFed tries to avoid the need for all of that by an automated system of its own, applied to each user evenly across the board - e.g. if you have more downvotes than upvotes, then an icon appears next to your name (this system seems able to be gamed though, especially wrt such ideological differences where many would upvote while many others would downvote, each side having different ideals about what is to be considered worthy).