I used to do "semi-sumo," too. I was red-lighted in competition for it, so I switched to a much more narrow position... leading to a very fast and clean pull off the floor and a slightly tougher lock-out.
I'm inclined to agree with Ouroborus here. That was a magnificent pull. The lock-out was a little sloppy, but not terrible. I'd also agree with adding in some more upper back work, though. I think the issue with that lock-out was your upper back not staying tight enough and being slightly hunched forward.. so your hips had to sidle underneath your shoulders and THEN complete the lock-out. I don't know if that makes much sense. But basically, it looks like if your back had stayed tight, the weight would've been supported by your hips a lot sooner and thus had a more "powerful" lock-out.
Maybe some partials would help, too, but it sounds like you're already doing that. Overall, I wouldn't worry too much. Progress slows as we do this longer and longer.