It’s fairly well known that marijuana has a bad effect on your testosterone levels via increased aromatase activity. Your T levels have a great effect on your EQ levels. If I’m not mistaken it increases your prolactin levels which could have an effect you on your EQ and refractory as well.
I would say for stretching ,, the more flacid the better,, if you have ever tried stretching with a little bit of erection,, its almost imposible hing
Focus more on stretching if going simply for length. Jelqing is much more of a girth exercise than a length exercise, however it is also good for overall penis health which is why it is included. Jelq around 25% or 30% for length. That way a decent stretch is achieved while maintaining decent expansion. Additionally the blood will accumulate the most at the end of the CCs beneath the glans and cause the ends to stretch the most.
Although don’t take my word for the absolute truth, perhaps a vet would have better knowledge on the subject of jelqing for length.
Best of luck to all fellow PE-ers in their journey.