The lid end point of the spring is always at the maximum throw of the spring. Everything else scales to that. There is a variable as to how far inside the lid the spring is mounted.

The end point of the lid isn't even depicted. It's not relevant. If you're talking about opening and closing, again, move the angle slider. But it's still only relevant if you want to change the fully-open angle. The compression of the spring is going to be reasonably linear through the opening/closing motion.