I’m in the exact same boat as you. Was gaining girth but no length. I added hanging and manual stretching to try and jump start length. Nothing to speak of on length yet but it has only been a little over a month I will let you know.
I also plan to do what you are talking about on the pumping side with the new tube I just got. Once I have gained enough girth to pack this new tube I’m going to stick with it anyway until I can pack it length wise also. I tried going back to my old tube to do that but it is way to small now and just causes pain way before it stretches length wise. So I will have to wait until I can pack the new one.