  Recently, it has been proven that a tensegrity framework that arises from
coning the one-skeleton of a convex polytope is rigid. Since such frameworks
are not always infinitesimally rigid, this leaves open the question as to
whether they are at least prestress stable. We prove here that this holds
subject to an intriguing new conjecture about coned polytope frameworks, that
we call the stress-flex conjecture. Multiple numerical experiments suggest that
this conjecture is true, and most surprisingly, seems to hold even beyond
convexity and also for higher genus~polytopes.
