Just keep that in mind. You really could make it a lot higher to really make your opponent step out of the court to get behind the shuttle. Therefore, I would also suggest a longer movement with more pronation, but maybe I'm just old-school in this regard. In my opinion, a short serve from the longer motion is more difficult and/or more obvious, but that's when you can make use of that almost swip like serve you use now (but built up the same way like the other serves of course).
I know what you mean - on some serves it's borderline that my right foot leaves the ground at around the exact moment of impact. I have to make sure to turn the foot and lift the heel but still keep the toes on the ground. We've discussed that before - that hall is just too low to deliver really high serves or even high defensive clears. Sadly, it's the only venue with rental courts with a 60 km radius. A good deceptive forehand swip/flick could be a mean option, very true. This goes along well with the plan to work on short forehand serves in general.
You need a bigger swing. To do this: 1. Lean the racket head a bit more towards the floor, than to the side; 2. Loosen your arm and body. I can see from the video that your arm is pretty stiff; 3. Adjust your elbow (the always-leading body part when making any shot). Your elbow should go a bit higher and a bit to the back. 4. Execute a full up and down swing, like weaving a whiplash. Don't rush. Imagine yourself being a big ocean wave. Implement these corrections with precision and direction. Add some power later. And don't worry, it's not an easy shot, plus in competitive men singles you'll most often use backhand serves for both short and long.
Lol - I will play this back to you as I can make the question sound very silly: "Will professionals hit harder than they can control for any reason?" - obviously the answer is no. You haven't practiced enough high serves yet to be able to feel the control when hitting it hard upwards for a serve like that - the truth is most people haven't. If you practice more, you will learn to hit harder whilst retaining control. The best way to learn is hit with control, then try to hit slightly harder than you are comfortable with. You will gradually improve your ability. I hold back on how hard I could hit because if I try to hit harder, my shots don't always go in. That is an unacceptable error. However, my shuttle already falls vertically and goes plenty high enough. Is there a benefit to hitting it higher? Only this: if I played at a bigger venue with a more swirling air current, the height of the shot would make it more difficult for my opponent to time their shot because it becomes more difficult to track the shuttle. Do I care about this? No. If I get good enough to care about whether I need to force my opponent to mishit off my serve because I can't beat him otherwise, I am in the wrong league. Good luck!
It seems we have come round in a circle from saying "higher is better" to "there's a limit where more power is not much more useful, regardless of your physical ability to hit it higher". Now I wish someone could definitively say what this minimum height for a vertical falling shuttle is! I might be reaching it already with 90% power and I just need to gain more accuracy, or I might still be under this minimum height. I reckon serve height would be a more interesting number than the smash heights they seem to love showing...
In all seriousness, 10 or 11 metres might not be far off. "high enough" is when you yourself are surprised how high it went, because its significantly higher than any lift in any rally would ever be. In general, "higher is better" is true for every single player that will ever bother to use a high serve, including professionals who would choose to hit higher if they could do so with accuracy. But im not sure why the conclusion "as high as possible given your current ability with full control" would be a surprise...
I would say it needs to be high enough so that after your opponent moves into position, they need to wait 1-2s before being able to hit the shuttle.
