Of the two, my biggest concern would be the amount of money that Mexico would expect to get from the United States and Canada for signing up for such a BS concept.
Even more frightening would be the willingness of some politicians to send frigging wheelbarrows of taxpayer cash south of the border in exchange for...
for....
uh....
anyone?
Oh, silly me. We'd get more Mexican political corruption and even MORE "guest workers" flooding across the border because none of that aid money is actually filtering down to the campesinos.
The ONLY and I mean ONLY way I'd agree to anything like this is if every Mexican politician, police officer, and public official/employee at federal, state, and local levels agreed to be executed.
That's the only way that Mexico would ever get even the remotest chance at a clean slate restart.