Right now, nowhere on lemmy that I've found.
Mind you, it isn't every person, but all the vegan communities and instances are currently run by militants of some degree. The .world one is the least militant that I've run across.
They aren't all rude, but definitely have the kind of thinking that leads to rudeness eventually.
Which really sucks because there's plenty of really chill vegans on lemmy. But you can't talk to them in vegan spaces without it being a problem unless you're parroting the scripture of vegan to their satisfaction.
Being real, I kinda wish someone would start a decent relaxed community.