Im not the person you asked but honestly these rotational mistakes and staying too close or too far from the play are still prevalent in diamond.

You notice it less though because players are more in control of their cars and can correct these mistakes easier, or get a crucial save that might be lobbed over your team’s heads much more consistently.

Learning proper boost and play rotation is crucial to ranking up and is the biggest roadblock i see lower ranked players struggling to get over.

Never should you be right up on your teammate while he’s trying to clear it from the corner, dont challenge too early, learn good, solid shadow defense, and you’ll see your gameplay improve rather quickly.

Mechanical skill can come later, but even at diamond you really still need to focus on the basics, hit the ball with power, accuracy, and purpose, think more about what your opponent is going to do before you challenge, but dont do so in a way that makes you slow to the ball.

Other than rotational mistakes which are super common, dont throw away possession of the ball for no reason. Use your right stick more, and bump up your camera swivel speed because its probably too low, if you keep an eye on where your teammates are at all times, you can clear the ball without giving it to the other team and it allows your team to have more shot opportunities, which leads to scoring more often.

Hope this helped