The above pics show a single row 1 ton AGE airdrop. You can see the extractor parachute attached to the bomb rack at the top of pic 1. The second pic shows how those neat and tidy para bags have been tangled into a rat's nest by the turbulent airflow around the rear of the a/c. This of course is with the ramp and door open, by as dragartist will no doubt confirm the air behind the a/c was always turbulent whatever the a/c configuration.
I could never feel any real difference in airflow when standing in the para door whether the air deflectors were open or shut. But closing the para door without them open was rather more difficult.
The ALM's used to get some stick from the menders for the state of the airframe in the vicinity of the para door locks. This was due to trying to close the door in flight in one smooth motion. One of the JENGOs made the mistake of offering to show us how it should be done ! It was very easy on the ground but I took him flying. He never did get it properly shut despite several attempts. Life aloft is never quite the same as life below.