7" is good. I run 7" in the front and 6" in the back. Helpers in the front. I don't mind lifting a wheels sometimes in the rear. But if you are worried, just run a helper.
Yeah, it would take me jumping my car to unseat my springs. also, roads where I live are no where near a bumpy as the road in that video. That's just some east coast rolling country road. Out here in CA we have not the smoothest roads, but nothing like that. I rarely get over 2" of movement.
So, no worries. Just zip tie the upper cone perch to the spring, and don't worry.