Ok, Let me preface this by saying I've only been PE'ing for a couple of months, but I did alter JP's program by adding a different Jelq. I only performed it for a week or so, but I've seen noticable growth in my glans size.
I have a high LOT, I guess aroudn 10:00 so I thought that maybe the Jelq's I was doing were supposed to be out to 10:00 or so, instead of straight out, but it's really using the standard Jelq grip for an angle above 90 degrees,
Also, when I'm hard my dick sticks up 45 degrees above the vertical -> / <- like this.
I mention these because they might be significant, who knows?
Anyways, for the exercise:
After getting that 70-80% erection, I'd take an ok grip, with my palm facing the same way as if I was pissing, at the base of my dick, and squeeze. Now when I jelq straight up, the blood in my dick, moves much more easily. And with a light grip, I can feel the blood rushing to my head, so much so that if you did it harder, it would hurt, like you were trying to pop the head.
I think the difference was the angle and erection level, although to be honest, I really have never heard of a 60-70% erection level, so it's been hard for me to be accurrate with the 70-80%. Also, I'm new to this and I've heard that Jelqing at 100% erection is harmful, as you can burst the blood vessels, so before trying this out, for my sake, let one of the pro's add some input. Because you wouldn't want the head of your dick to explode. Truth.