Being an extreme example of how wholesomeness, warmth, compassion and kindness are not at odds with first-principle thinking on the internet would be incredible. I do think the forum has moved in this direction in recent years but I definitely don’t think it’s maxed out “warmth” while still satisfying the constraint “everyone still care lots about what is actually true”.

I do think making first-principle thinking “warm” is really hard. Science communicators have a really tough time coming across as knowledgeable and warm at the same time (see 6.3 of this article for a discussion -  https://royalsocietypublishing.org/doi/10.1098/rsos.181870#d3e2150). Adjacent communities to the effective altruism community with online spaces are often quite cold and direct (rationality, economics, computer science all have quite cold online spaces). I do think that naturally, the EA forum has taken a lot from that side of its adjacent culture (the “have a social impact” side tends to have a  warmer vibe so that is something that could maybe be leant on). Places where precision and truth are less core to the identity of the group often seem to be able to make warmth take up more space (eg. religious groups and naturopath groups are often about "love" and "care" and this is both explicitly and implicitly communicated - this is also often true in animal welfare groups and mental health support groups too).  

I do think the effective altruism forum often does a pretty good job of warmth sometimes, but I'd like to see this be a core part of the culture in an online space.  I also think effective altruism might have a shot at creating a culture where extreme compassion, warmth and wholesomeness can find a place alongside an extreme valuation of what is true. Effective altruism has a really good combo for creating a space like this:

1. Effective altruism is about helping others! Very wholesome!
2. People are more okay with seeing expressions of uncertainty as a virtue/a sign of expertise and not evidence against expertise. Uncertain statements - even ones that give a true impression of what one thinks - can be very useful for saying true things in a welcoming way that avoid triggering people’s natural insecurities. Uncertainty can maybe make it easier to maintain the "we're a team trying to help the world" vibe in every exchange. 
   
   Statements like "I am so glad we disagreed because we're trying to figure out how to help the world together and because no one knows all the answers, it's really valuable that our best guesses are different so we can learn from each other! Our disagreements only bring us closer to our common goal <3." as a sign-off to a discussion could perhaps be very common. Plus maybe a cultural norm of a few compliments at the end of almost every disagreement (or just random compliments everywhere - whenever anyone thinks of something nice and true to say) for good measure like "I thought that line of argument was very clever and not something that occurred to me before you brought it up, it did give me food for thought and I'll definitely simmer on it because of this discussion so thank you!" or "I know we didn't quite manage to cross that inferential gap, but I really enjoyed this discussion and I still felt like I learnt a lot!". Heart and rainbow emojis would also be everywhere.
   
    As I said above, this does happen sometimes, but I think the wholesomeness/warmth being completely and utterly over-the-top, especially if there was still this forum, might be refreshing and motivating. It might also allow effective altruism to reach new audiences who have similar values but don't feel as comfortable with the direct, cold STEM vibe that the current EA forum still has to a significant degree.  
   
   So to summarise, an online space where wholesomeness and warmth were valued to an extreme degree as a cultural norm but still, people didn’t shy away from saying what they thought as they do now, is not impossible and could maybe be pretty wonderful.

Way more casual - maybe more like Reddit, but with easier delineation between communities (ranging from cause areas to identities).

So, a mix of Reddit and Facebook, but with better quality norms. Maybe if the EA Hub started a Forum, I guess.

Friendly/sarcastic

A warmer aesthetic, with better image support and emoticons. Aim for shorter text for a non-expert audience and meme generation.

Spanish speaking

The forum is the same but you can only type in Spanish.