I’m not sure if I should push my hips trough faster or purposely round more over at my upper back. Any advice would be appreciated.
Don’t worry about changing anything yet. You didn’t reveal any glaring weakness there, so keep adding weight until it actually gets hard for you.
Good lift. The hips are set too high for a sumo deadlift IMO. This contributes to your shoulders being over the bar rather than behind the bar and you lifting backwards before you finish the leg drive. Furthermore, the knees look to be in need of opening up more to allow the bar to be set closer to the hips. A good sumo pull has almost two components: a) drive with the legs and the back is held at a static angle and b) a push through with the hips. This is only possible if the starting position is improved. Nonetheless, this is not bad form to work from.
I think whether you round your shoulders or not depends on where you have more difficulty. I pull with a hook grip and rounded shoulders and hit helps it come off the floor faster. Where it has a negative effect is locking out. Your shoulders are rounded forward and getting your hips through and shoulders back at the top becomes more difficult.
Those looked nice.