Opening and closing doors for para work would (in my time) be frowned on. Door, and (on the Bev) hatch surrounds, were carefully checked before flight for slightest damage (possibly apocryphal story of Gus Appleyard and the Bev boom hatch).Sticking one's head into the slipstream on the rtb gave a marvellous head massage ! Removing the clamshell doors on the Bev (for combined heavy drop and para, required the fitting of 'elephant ears' - otherwise boom departures would end up back in the freight bay !!
A remarlable tale of PJI actions was of Robbie R - No 1 despatcher on a Hastings drop. The No1 stood centrally at the rear of the aircraft and was the final monitoring check for the despatch process. He saw one of the stick with his static line not hooked on and grabbed the line, braced across the door and the 'chute deployed. (Final tie cord breaking strain was approx. 700pounds.!) Note that we dropped
without reserve 'chutes.