Hi Misd Agin,
As far as I know, Boeing recommends the largest flap setting for the actual weight, to increase tail clearance, among others. We operate our 800s out of rather long runways and even at max passenger capacity, our surplus wt is normally huge. This means we use flaps 10 as a primary flap setting and we decrease it to 5 if performance limited, we then use 5 and bleeds off if performance is still a problem.
I understand boeing does not support two-step rotation techniques, like the one you mention, but it sounds like a good one.
Thank you for the contributions.
Regards,
SW.