For reference this is a 5/8 lock nut with an Allen screw inside. It was so seized up, we let it soak for 3 days with antiseize, tried head and freeze method, and nothing helped. Still ended up with a stripped screw. I’m at a loss at this point and not sure I feel comfortable grinding a notch into it.
That’s not a bad idea. It’s a lock nut so it has to be loosened first in order to get the screw free, so it’s kind of a pain in the ass. The torx isn’t a bad idea. I thought about rec welding an Allen key into it and just leaving it but I decided against that idea for now.