It's actually better kneeling but after you get done the entire stack it's impossible to get into position. the trick is that you can get a ton of stretch
from having the elbows way back without putting strain on the shoulders.
For comparison I overhead tri ext a 115 for 12
the high reps is just an artifact of where I am in a DC blast right now, which happens to also be the strongest I've ever been. The reps will come down a little as the weight goes up. I always do low reps for deadlifts - I like low reps on all my major lifts, I had good 531 progress this spring.
EDIT -Re: chunks video. It works a ton better if the cable pivot is at like chest height, otherwise it cuts the ROM.