Must the listener prostrate if the reciter is outside of prayer and the listener is in a supererogatory (nafl) prayer?

Primary text

If the reciter is outside of prayer and the listener is in a supererogatory prayer, there are two narrations. The correct view is that the listener does not prostrate and should not listen, but rather should occupy themselves with their own prayer. This is supported by the Prophet's statement, "Indeed, in prayer there is preoccupation," which is agreed upon (Muttafaq 'alayh).