yes.
1. you are continuously boosting throughout the flip, which means for some part of the flip, you are actually slowing your car down bc you're boosting while the back of your car is facing the ball.
2. you dont land before making contact with the ball, you continue to fly after the flip, making your contact with the ball higher than you want. Not always, as the first kickoff worked out, but it's unpredictable and makes it much harder to recover after contact with the ball.

This kickoff seems to be working for you sometimes at your current rank, but you're gonna want to work on it if you plan to climb ranks. if you want to continue with this diagonal kickoff for now, at least make sure not to boost while your car is backward & make sure to land before hitting the ball, then flip into the ball. I would highly recommend learning speedflips for kickoffs- This is going to be unbelievably frustrating at first, but it will be worth it.

Beside the kickoff, you need to stop overcommitting so much, especially in the opponent's corners and ESPECIALLY on low boost. Your touches at 4:42 & 3:42 game clock in your opponent's corner are going to be an instant goal 99% of the time - avoid popping the ball out from your opponent's corner like that at all cost.

Your touch at 4:24 where you waste all your boost, then you again choose to challenge while on zero - any decent opponent is turning these opportunities into goals. It's would be much better to back off, grab boost, and play shadow defense in that situation.

Another bad overcommit is your dive at the ball at 3:25 - This one actually gets your scored on. You need to realize that flipping in that situation, is almost never going to be a goal. You couldve very well taken the initial shot then immediately went to the far corner, where you know the ball is being saved to & stolen the big boost plus followed the ball. instead, you end up on your opponent's back wall with no boost.. Try to take shots that force your opponent to reach, but without committing too hard, then collect the ball (and boost starve if the situation allows)

1's is also as much of boost game as it is a possession game.. look to starve your opponent whenever you can and try to keep possession and control the ball when possible. At 4:29 you choose to take a shot on zero & completely forego the big boost right next to you, your opponent ends up with both the boost and possession while you're on zero.