I've seen safety cases and can confirn that, in my opinion (given free to all readers), they are the largest waste of money ever given to so-callled safety engineers.
Safety cases are an over-rated system of ever decreasing argument against any action anyone would want to make to improve an operation. The series of nit-picking and smugness from said SE's is astounding and unbelieveable. And their wages are unsustainable considering the profit they rob from the company.
It is the one "standard" that everyone should rightly ignore until it goes away.