Nothing can replace NdFeB magnets on the manufacturing horizon. Fe16-N2 Alpha” phase is such an elusive metastable state, it can only stay in the literature for academics.
If without rare earth hard to achieve static retaining of magnetic orientation, perhaps some kind of dynamic recharging of energy to the electrons. Have somebody thought of dynamic charging at the natural oscillation frequency of the atom structure, which definitely will be very high frequency, but perhaps, doable... Heheheh