Where

I've been reading lately that some of u stretch when 20-80% erect. Is it more effective to stretch slightly erect or totally flaccid?

Second question, when im 15-20% erect the ligament is lose. my cock hangs lower. Where does this length come from? When 80-100% erect, i understand why the lig is stretched out longer, but at 20%, no clue
??? ?

Forget about the first question, i done a search; sorry.