It's really hard to tell from the film, but...from your starting position, where your left hand is - that crack sorta slopes down then rises. Maybe try your right foot there in that pocket? It just seems like that right foot needs to be on something there to get the move up with the left hand.
Thunder is a vicious sorta project. Just every move feels uncomfortable until you give yourself time on it. If you're still projecting this, I strongly recommend bringing folks out to spot for the top out. The angle can eject you out and off the landing if you punt off the top and having a spotter below the rock/branch wall to push you toward pads could be a life saver.
A little unsolicited suggestion: I think that heelhook is the way to go, but the right foot is keeping you from using it properly. When you put the left heel in place let go of that right foothold and just open your right leg to the right to where your body position demands, dragging the right foot on the wall. This will unlock the left heelhook potential (as your center of gravity falling to the right side will put more friction on the heel which, at the same time, will be putting the force on the wall in the right direction. Plus the right foot dragging will keep the body in place, nicely close to the wall, and will generate a bit more friction on the heel as a kinda opposing force). Stoked to see you send man! Good luck
