I have a lot of foreskin, but yet, it is easier to jelq with KY, more freedom in the hands. I only have to focus on the grip not if my skin is stretched or if am putting more force on the skin than needed, or if I am being brutal or or or or or or or or or. Nothing. Plus it is for sure easier for the skin and being a beginner I prefer the easy way while I am getting stronger there.
And, yes, dry jelq causes more friction than wet jelq and anyone who says the opposite is just not using right lubrication.