Getting back to it

Ok, so I’ve owned the x4 labs extender for about a year now however haven’t used it as much as I should, and when I did use it I would stretch to the max and leave it for an hour then take a break and repeat a few times a day. However I’m thinking I was doing it wrong. To my understanding it’s only stretched out enough to feel a gentle pull and then left. The point in it is just to have constant tension? How much tension is enough?