There was of course the space cadet at Scampton who, when the aircraft blew up, evacuated the aircraft with his parachute and static line still connected. The chute deployed as he departed stage left.
I guess thinbgs tightened up considerably as gravity took its inevitable toll. When first on the beast we often flew unstraped and bone domes off, even at low level. Just 5 years later I wore a Mk 2 hat all the time and also parachute, even when going down tot he prone position. I would only remove it for high level astro or where I had to get into awkward spaces for fuse changing.