This can't work. Patent law changes and is often retro-actively applied. Though to your point, AFAIK examiners and their bosses hate to have patents they allow

This can't work. Patent law changes and is often retro-actively applied. Though to your point, AFAIK examiners and their bosses hate to have patents they allow be overturned. It is noticed. But often, patents are invalidated based on changes to the law that occur after a patent was allowed.