I would have thought that you would need parachute training to use a square chute. Very few aircrew every jump for fun.
While a square chute and a high abandonment may help you steer away it probably unlikely that you would see the bad guys on the ground early enough anyway. For a last second abandonment you need as much chute as possible and no finesse.
Another consideration may be the chute pack size. Certainly, IIRC, the Army chutes were 28 foot diameter (and greater load of course) compared with the aircrew ones at 24 feet. That works out with a difference in size of about 10%.