Living the dream
I agree wholeheartedly with you. Auto is quite clearly more accurate, but that's predicated on not being a dufus with the lineup.
That will come with time. Keep working.
Try to eliminate variables. Start by getting your designation as early as possible, get it sweet prior to roll in, DON'T J-HOOK, keep AFC engaged the whole time, and then just roll in the same way every time.
Before long you'll be wondering what to do with all that tracking time. 8-10 seconds is a long time to sweeten lineup and tweak airspeed.
Then again, the majority of drops you do in the fleet/combat will probably be PGMs, so that kind of takes the fun out of all of that stuff above.