I think it very much depends. There were the generation of British pilots brought up on open cockpit fighters- Gauntlet, Bulldog etc, who may have found their lookout more limited by the canopies than they would have liked. I recall reading somewhere (no reference to hand so take it with a pinch of salt) there were also issues wth opening the canopies of early marks of Spitfire, especially when the fuel tank in front of your knees was on fire, in order to get out in a hurry. Some nations-the Italians most notably but also Russia, were very slow to adopt enclosed cockpits. Me109, 110, 210, 410 pilots couldn't as the canopy/panels would have disappeared quite rapidly, but Fw190 pilots could, and perhaps did. As you look further forward most USN carrier aircraft in the '50's were usually catapulted with canopy open to ease escape if it went quiet as one shot over the bow. You have picked a broad (20 year) timespan when a lot of things were happening in aviation. Perhaps narrowing down the question to specific types/nations/conflicts would help you find an answer.