Same here. I use left-front, and I rarely use my rear brake at all. I'm fairly good at changing habits, but I don't think I should change this one. I'm right handed, and I use my right hand for other duties, and my left hand has the reflex for braking, and it's coordinated and strong enough for the job. Fear of doing an endo is silly. I used to teach cycling skills, and my line is, "The risk of going over the handlebar from overuse of your brake is real but small."