Yes IPv4 on steroids. Providing artificial enhancement by placing the burden on edge routers. So if you've got to replace the edge routers you might as well replace them with IPv6 compatible kit and be done with it.
Oh look this EnIP breaks IPSec because its fudging the source and destination addresses.
This should be a research project and not billed as a solution.
Why, oh why? I can’t think of one good reason the effort put into this shouldn’t have gone instead into raising IPv6 adoption.