I’ve sat next to an Everton fan at the derby once, and he was fine. It does happen, from my experience it’s only cl matches where it gets a bit iffy. Few ajax fans last season over celebrated and wound up a lot in the home end, ended up getting kicked out because it got a bit physical in the end. Shout out to Villareal fans, they had loads in the home end during the CL semi the other year, and they were a great bunch.