Let's end this debate: a proof does not create an equivalence, it reveals it, no more, no less.
The equivalence between sensitivities based on fixed points and those of KKT is an intrinsic property to discover, not to manufacture.
We must decide whether this equivalence holds under all market conditions, especially in the case of sovereign debt tension.
For example, an unexpected liquidity shock can call into question the relevance of this equivalence in risk modeling for Portuguese banks.
Let's set the application framework. Now.