I'm in the same boat as you, buddy. I've always thought that I defied the norms because my BPFSL never exceeded my BPEL; in fact, it was always an 1" or more short. Only way I could make it even anywhere close to my BPEL is to fill some blood in it and it will slightly stretch more.
My grip keeps slipping for stretching (to the point where I could only hold each directional stretch for 15 sec max) so I want to invest in hanging, but I don't have the privacy and it's less convenient than stretching because essentially, you could only do it at home and I'm out most of the day so that just leaves manual stretching for me to use (or an extender, but I don't like the way that contraption is designed).
Any tips on how to incorporate a better grip or why this occurs. I believe it's what's really holding me back and the reason I haven't made any length gains in like 7 months.