I would change your amnesty program in this respect: Create a new category called "Permanent Guest Worker." This new "Blue Card" would afford the recipient all of the rights and privileges of a Green Card holder, with the exception that there is no possibility for a path to citizenship.
In order to become a citizen, the individual must return to their native country and apply for reentry along with all other applicants in their home country.
“Create a new category called ‘Permanent Guest Worker.’”
It has good potential, I’ll be thinking about that for some time.