We propose a continuation experiment for the detection set-up upgrade on VESUVIO. This is set into a programme to increase the spectrometer sensitivity up to an order of magnitude, aiming at increasing the accuracy of DINS measurements of momentum distribution line shapes. In particular, we propose to test the improved performances on a series of hydrogenous samples with similar stoichiometry but expected to show different degrees of anisotropy of the hydrogen local potential, reflected in changes on the momentum distribution line shape. The low-level discrimination threshold of the detectors will be lowered from the usual value of 600 keV, to the value of 60 keV, for in this configuration we observed a fourfold increase of the count rate. We propose now an additional modification of the set-up so as to concurrently decrease the detected background.