I have been engaged in warfare with hedge trees since 1997 when we bought our place.
Remove them. But know what you are getting into. They are twisted up, often you cant tell what way they will fall if they are bigger trees and as you piece them out branch by branch they will hang up, bind your saw, tear you up with thorns and actively resist you. If you start on one in the spring and don’t finish it, when you come back the next spring it will have sprouted a shield active counter measures (thorns).
I took gobs of them out of my pasture/now food plot areas in the late 90’s. The stumps are still there and I work on them when I can. What is incredible to me is the stump/base of the tree material is impervious to rot. It is still there. If I pull it out of the ground its dry, hard as a rock.
Nothing burns like hedge. It’s the coal of firewood. In my area in the 70’s and early 80’s a lot of people had cast iron Franklin wood stoves. People were cutting up anything they could find back then. If they didn’t know what it was, some people would burn the knobs off their doors with hedge.
I have a really big one I want to take out and if I can get it out of there it opens up a lane I can walk and drive a tractor along a fence line. I might start on it this winter. I’m really not looking forward to it. It’s base is like a 100 year old oak tree.