In the final part, we present an algorithm for the optimization of the field profile based on the knowledge on the field dependence of PHIP transfer efficiency. We compare it with the linear profile under similar experimental conditions to prove the validity of our reasoning. It should be stressed that this approach is applicable not only to PHIP, but also to any other method of hyperpolarization, or any other NMR experiment exploiting adiabatic variations of Hamiltonian.