I think admitting a convention refugee from the States would so offend them that the consequences are going to prevent it from ever happening de jure. (I also think climate refugees are going to de jure collapse the convention; that's already close to having happened de facto.)

And, yes, that's what is supposed to happen and the states retain some measure of sovereignty and none of it matters if there's no means to enforce the laws. It's the "no means to enforce" that I'm expecting; it fits with the Russian-asset version of things, it fits with the "none dare refuse" CEO mindset, and it fits with the dementia. It intensely fits with the confederate desire to use the USG as a means of oppressing everyone they don't like, too, as well as the function of police forces as instruments of white supremacy.

Hopefully I am being unduly pessimistic.