For Dogfighting or Bombing in an A20, there is no way I can use the F3 mode, I can't see where I'm shooting, and can't eye my speed and other factors needed for a proper dogfight in the plane. I do use it for taking screenshots of buffs and reviewing bullet holes while refueling... (Call me a dweeb).
The A20 will be just as effective w/o F3 mode. It's a monster of a plane if you take a little patience to fly it. Quit complaining about F3 because it's a crutch that will keep you from advancing as a pilot. Instead, try learning to fly the A20, learn it's strengths and weaknesses, and learn to exploit these the next time you fight one. You might find a different outcome.
I fought Cobia the other night, he was A20, I was a Zeke, he had a ton of smack on me, and I managed to turn the tables and get him roped. He managed a ping on me and took an aileron, but in the end, he had to breakoff his attack or get smacked by others. 2 Months ago, Cobia would have eaten me alive... but I decided to learn what the A20 can do, rather than whine and moan that someone can use it better than me.