Are we arguing the same thing? If UAF is the cause of security problems, and UAF is undefined behavior now, redefining it under a special mode to mean "this is an error (whether or not the compiler enforces it)" at least clarifies the situation,and lets and included static analysis report an error as needed and capable.

That is, I'm not arguing that as much undefined behavior as possible should be made defined and possible, just that it's defined. That definition may very well be "you are not allowed to do this. Don't do this."