It is not the magnitude of the current being broken but the magnitude of the stored energy on the inductor when the current is broken and the back EMF created when the nagnetic field is collapsing.
Yes, but that's really just a play on words, since the 'magnitude of stored energy' (stored in magnetic field) is, itself, determined by the magnitude of the current.
In fact, since that stored energy is given by LI²/2, the fact that it is a function of I², rather than just I, means that the stored energy increases rapidly as current increases.
Kind Regards, John