I’m not a big PE theorist but here’s one theory I try to apply
I think there are 2 categories of exercises: 1-stretching exercises 2-Engorgement exercises
I think you can max out the results you get by focusing on only 1 category at the time.
I’ve always worked more with stretching exercises (manual stretches, long sessions of very low erection level jelqs). I got good gains from it but I hit a plateau for a while.
Right now, I’m focusing on engorgement exercises. I made myself a routine consisting of 3 sets where I alternate dry jelqing/ manual clamping/ edging and high pressure pumping (between 10 and 15 Hg).
So far it seems to be working good for me. I have gained a little bit and I definitely broke the plateau where I was stuck.
I also think that alternating between stretching routines and engorgement routines allows you to get repeated gains from certain exercises. Example: my first routine ever consisted of stretches only. I made very quick newbie gains of 3cm (a little over 1”). After I made those gains, I stuck with this routine for an other year and gained nothing. I switched to a jelqing routine for about a year. Didn’t gain much with the jelqing (no length and a little bit of girth). After my year off from stretching, I went back to my old stretching routine and I gained an other 1cm (+- 7/16”) in about 2 weeks. I then hit a plateau again. I am planning to go back to this same stretching routine when I stop gaining from my actual engorgement routine. Then I’ll be able to say if this “theory” of repeated gains has any value.
As far as your original question is concerned, I think it is a great idea to hang and pump but I’d definitely do each of them in separated routines at separated times. Something like a stretching/hanging routine for a few months and then I’d switch to a pumping/engorgement routine for a few months. But then again, I ain’t no PE scientist…