My current FS is about 165/170kg for a single. Or 140kg for 6. Back squat - I was doing 200kg for singles back in March. I’m not any weaker. So maybe 210/220kg? Not maxed out for a while.
That second video looked better. Your hips still look to come up a touch quick. But no where near like the first video.
A belt will help. I’m not sure on your bracing. But a belt could help with that.
I’d wait. Use a solid programme to progress and then come back. The 531 loading scheme works for all lifts. Look into that. If not the below programme is for dead lifts - but it will work for any lower body lift really.