The amount of emitted prompt neutrons from the fission fragments increases as a function of excitation energy. Yet it is not fully understood whether the increase in u(A) as a function of E_{n} is mass dependent. The share of excitation energies among the fragments is still under debate, but there are reasons to believe that the excess in neutron emission originates only from the heavy fragments, leaving u_{light}(A) almost unchanged. In this work we investigated the consequences of a mass-dependent increase in u(A) on the final mass and energy distributions. The assumptions on u(A) are essential when analysing measurements based on the 2E-technique. This choice showed to be significant on the measured observables. For example, the post-neutron emission mass yield distribution revealed changes up to 10-30%. The outcome of this work pinpoint the urgent need to determine u(A) experimentally, and in particular, how u(A) changes as a function of incident-neutron energy. Until then, many fission yields in the data libraries could be largely affected, since they were analysed based on another assumption on the neutron emission.
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