If retirement savings are planned responsibility it should be a pot of money that you take with you from State to state like any other property.
No State should have the practical authority to do otherwise having not possession of the property.
The real key to maintaining interstate liberty is the very fact that States are not abridged to always respect the laws and demands of other states, particularly when those laws seem only designed to disadvantageous other states or rob people of their ability to flee with their resources.
It is thus much easier thing for Congress to Abolish barriers to interstate trade than to establish domestic order. One act requires a standing intrastate army the other simply requires that they occasionally take sides between two disputing states.
If on the other hand people decide to give their state Government full possession and control of their retirement plan that is no different than investing in the judgement of that Government.
Sorry, but you are talking shoulds and ifs.
That’s supreme freaking court had to rule to protect even military retirements from several states.
I give an example and you say it’s basically the individuals own fault.
My point remains the same ... individual state nullification of SCOTUS is a dangerous game. It will cut two ways, and likely lead to confrontation over enforcement. And that enforcement will come from the Feds.