Your mechanics are poor. I'm not sure why you're hopping into the shot? Both of your feet are off the ice at one point. The puck is also way too far ahead of you. You are not using any of your core or body weight when shooting. It is all arms. Lean forward on your stick more, bend the front knee, and let the stick do the work. I'm not sure what your skill level is, but off-foot snapshots are not really recommended for players below an advanced level. Off-foot snapshots are also not going to ever be your hardest shot. They are utilized mostly because the release is much quicker than a typical wrist/snapshot, because you don't have the big weight transfer of a standard wrist shot or snap shot.
If you are looking for maximum power, you are shooting off the wrong foot.
I wouldn't say his mechanics are poor, just need tweaking. Watching a few BASE videos they try to highlight the positive aspects in the analysis and there a some good things happening. Also it appears obvious the OP has a lot of experience based on the fact he can even perform a decent looking OFSS. I'm not sure I agree about it not being your hardest shot. Sure Ovechkin in the right position would rather a 1/2 slapper but for good reason off-foot has become the favored shot in hockey. In motion it can really sizzle.
OP- I 100% agree the jump at the beginning of the weight transfer is off. In the pro example there is a very slight leap... here it's huge jump and the motion is exaggerated wildly, throwing you off balance and wasting energy. Just need to tone the leap down and focus on bending the front leg deeper.
I agree with pp that you're not driving through enough. Notice the front foot is curving away from net. If the front foot can aim forward more it facilitate complete rotation and ending the shot leaning over the front foot. The video's say at completion your ear should be ahead of the front skate.
A big thing I notice is you're not looking directly at the net. You're peeking at the puck and partly the net until :06 when the head finally comes "up". Head has to be locked in at the target the entire way. This summer on the practice-pad I've focused on just this, resisting my terrible habit of looking at the puck before/during shooting. It's a tough habit to break but after time I'm improving a little.
It should be noted your shot is different than the usual shot training videos because of the approach to the puck from a distance. Here it's almost an off-foot slap shot if you see what I'm trying to say. I'd be curious to see the difference moving forward with the puck in a traditional manner instead.
2:25 is a great breakdown of shooting technique. It's fascinating the fundamentals of the wrister apply to all the rest of the shots.