Here's my 2 cents. My dad taught me how to shoot for hunting purposes. You take your time and make one perfect shot. Then I got into shooting sports and I needed to learn a different way to shoot. Luckily for me, my best friend is in the military and serves with the best unit we have. He's been trained by some of the best shooters, example one being Jerry Miculek. He taught me how to shoot everything faster and more accurate. Since you have the other two guns covered, I'll just go over the rifle. When you shoot you should notice your rifles muzzle movement. Most of the time on a right handed shooter it should track in a clockwise circle moving up and to the right. The key to shooting fast and accurate is practicing and being fully aware how the gun moves. I will note that with my new compensator that circle is indeed much tighter. Once you learn that circle and the timing you just let the gun do its movement and time your shots. Other things that help is a firm hold on your rifle, support hand extended out as far as your comfortable, athletic stance leaning forward slightly and "driving" your shots. That also helps with recoil management.
I personally run a 15" keymod rail and have my support hand all the way out to the end, been considering a longer handguard for a little extra reach. But I'm taller with a long wingspan. It might be hard to understand what I'm saying, but if you go and shoot your rifle you should see the circle I'm talking about.
One last thing, get a 1-4x 1-6x or 1-8x scope. 5x that close is too much. I personally use 1x almost all the time. But it depends on the stage setup. If the stage has all close range targets and one at 100 I'll just shoot the whole stage at 1x. But if the stage has a couple close targets and a bunch of 100 yard + targets I'll start on 1x and when I get to the long range I'll throw the magnification up a little higher, this is where the switchview comes in handy. If you can hit your targets at 100 yards with 1x it's not worth the time to switch, but if you struggle then I'd take the second the change the magnification.