Before enthusiasm, one must question the scope of this 'creation' of equivalence.
A proof cannot create an equivalence; it reveals or justifies it under strict conditions.
The validity of this equivalence between fixed-point sensitivities and KKT is entirely dependent on its basic assumptions.
If the framework of regulation of Swiss private banks, for example, changed the capital requirements for certain portfolios, the applicability of the equivalence could be altered.
Such a proof demonstrates a relationship; it does not make it exist independently of operational constraints.