Plate pinching is fun stuff. And considering the thumb is the other "half" of your grip, it pays to have a strong pinch. Don't be surprised if bringing the thumb up results in an overall increase in hand strength.
I'm not sure if it was identified on the video like I know the 35's and 10's were, but the 'release and catch' and double clean & press was done with 25's. I'm thinking I might try that again tomorrow after the contest with 35's though
And yes, they were 20kg (44lb) bumpers I was flipping at the end. The last attempt I did with my right hand I caught wrong and jammed the thumb pretty good, notice how I kinda grumble and curse as I walk away and all the attempts after were done with my left hand.