Thanks to those who have added to this discussion.
Let me use my own case as an example. I live in NJ, a "may issue" state which in practice will not issue to anyone except a retired police office or a professional armed guard. I am neither.
I have several non-resident out-of-state permits: FL, UT, CT. None of these non-resident permits are honored by SC, and they only issue their own SC permits to non-residents who are in the military, or owners of property in SC. So the way I see it, I could get a SC permit only by first buying some property there. To hold down the costs, it should be a small, almost worthless
patch, with inconsequential taxes.
It just means that SC is more restrictive for non-residents than many other states with the same color-code on the automated map.