How can manual stretching routines even work
I though this back when I was doing PE years ago. You have extenders that work when used for very many hours every day with tension 1-3 kg. Then you have hanging done usually at least hour a day every day or almost with usually higher load than extender. Then those old manual routines where you have 5-10 mins of manual stretching and done like 4-5 times a week. How can that do anything but some newbie gains? So little time under tension compared to those devices.
I used to do manual stretchin short sessions many times a day for total 20-30min time under tension and used ads to keep it elongated. That gave me some minor gains after 6 month hanging journey.