Ni Hao H and welcome to Epic!
Those last two heel side turns were great. Overall, you are showing strong knee angles and good edge engagement after the fall line on your heel side turns. The rest of the run shows good control (making turns where you want to) and a nice centered stance. But it's easy to see why you feel like your riding has hit a limit.
First off you need to bend your legs more. Aside from the shaky camera, you are also getting knocked around on the snow. The snow is quite bumpy in spots. You need to be using your legs as shock absorbers more. You will also benefit from using bending and unbending of the legs to help the feet turn easier. Think how martial artists rotating their fist when they punch. The same principle of the rotating fist making the unbending arm more powerful works to make an unbending leg make feet turning more powerful.
When your legs don't bend much, it's hard to rotate your feet to guide the board through a turn. So you end up pivoting the board by kicking your back foot out to start a turn. This is a slow way to start a turn, but it does work. It also leads to "Z" shaped turns where you kick the board out, set the new edge, skid to slow down, track in the new direction the board is pointing, then kick the back end of the board out to start to the next turn. These are effective turns on easier terrain, but they fall apart on steeper terrain and more difficult snow conditions.
On your toe side turns, you are not arching your back. It's possible to ride toe sides with a straight back, but there's no margin for error. Without highly skilled ankle movements, you end up having difficulty controlling balance and end up riding lower edge angles to avoid falling over. An arched back gives you the ability to pull your hips back if you get on too high of an edge and it also lets you open your ankles to create very high edge angles.
On your heel side turns, we want to start getting on the new edge above the fall line (i.e. engage the downhill edge at the end of a toe side turn in order to start a heel side turn). To do this we're going to have guide with the front foot more and pivot the back foot less. If you finish your heel side turns in a low position (with your legs bent), then straighten the legs while lifting the toes of the front and pressing the front little toe into the side of the boot (to rotate the foot) you'll be able to guide the board onto the new edge without catching it and crashing. The same principle will work for your toe side turns once we get your stance for those turns changed.
That's where I'd take you. To get there I'd start with two drills: Jack in the Box and Hail Mary.
We start the Jack in the Box drill riding with our hand on our knees all the time. Let your hands reach to your knees by bending your legs vs bending at the waist. Next whenever you want to start a new turn, rise up and touch both hands to hold your shoulders to start the turn and then quickly put your hands back on your knees as soon as possible. When you can do this ok, ride with your hands touching the tops of the boots. When you can do this riding with your hands touching your toes, you are finally doing more than enough leg bending for regular riding. For extra credit, ride touching the board on toe sides and grabbing the edge on heel sides. Whoa! The end result we want to achieve here is a rising movement to start your turns and sinking movement to finish them.
Hail Mary teaches you to arch your back. Stand on a flat spot (you can do this part of the exercise at home in bare feet or on the hill). Raise your arms straight over your head (arms locked straight!). Open your hands so that your palms face the sky. Feel your back arch automagically? Your belly button should move out a little bit closer to your knees. Now bend your legs to stand on your toes. In this position, you should be able to raise and lower your heels at will and move your hips up and down without losing balance. Now we are ready to ride. Whenever you make a toe side turn, raise your arms into the hail Mary position and then lower them back to the normal position for the heel side turn. After you get comfortable riding toe sides with your back arched, you should be able to do it without hailing Mary.
Thanks for joining Epic. These tips should help you break through to the next level of riding. Enjoy the ride!