“…A similar approach was developed for constructing solvable 3D models, which admit factorization of the respective 3D equation into a product of relatively simple 1D equations, which admit exact solutions (in particular, solitons) [73][74][75][76][77]. In fact, the integrability of such specially designed (engineered ) models is not a fundamentally new mathematical finding, because they may be transformed, by means of tricky but explicit transformations of the wave function (or several wave functions, in the case of multi-component systems), spatial coordinates, and the temporal variable, into the classical integrable 1D NLS equation with constant coefficients (or the Manakov's [78] integrable system of the NLS equations) [79,80]. Accordingly, a great variety of integrable and nearly integrable models can be generated by means of inverse engineering, applying generic transformations of the same type to the underlying integrable equation(s) [81].…”