static jumping, seat in, any advice?

Below I’ve inserted a slow motion video of my static, seat in jump. I did it in front of a picnic table just so you could see the approximate height. My estimation is that I’m getting around 10 inches, maybe a little more or a little less. From the looks of it, I am high enough to do a crank grab on the seat of the picnic table, but I would need another 4-5 inches before I could get my tire up there.

I know if I want to get really high, then I have to learn SIF jumping. However, I wanted to know if the more experienced riders could see any obvious mistakes in my static jumping form that could help me get higher.

I’m thinking of putting a little more air in my tire and also trying to swing my free arm more. Any other tips?