While I'm personally bias (see right above), from my experience the general content in alt right spaces (I've been on wolfballs, idk about exploding heads tho) is a bit more unhinged than general content on Marxist/left unity spaces. I mean we MLs agree with the "vaguely leftist" person more than a alt right person.

I personally like to try meeting people where they are and don't block as long as the content isn't harmful. And imho a random person on the internet saying a 19th century philosopher was right is not that harmful, especially compared to people down the alt right rabbit hole (yes I'm oversimplifing).