  Multiple intriguing low temperature phenomena have recently been discovered
in the family of chiral cubic Co-Zn-Mn compounds with $\beta-$Mn-type
structure. In particular, Co$_8$Zn$_8$Mn$_4$ displays a reduction of the
helical spiral pitch on cooling, along with lattice shape transformations of
metastable skyrmions and the manifestation of peculiar magnetic textures due to
strong magnetocrystalline anisotropy. Here we report on temperature-dependent
measurements of helimagnon excitations in the field polarized regime
Co$_8$Zn$_8$Mn$_4$ using the spin wave small-angle neutron scattering (SWSANS)
technique. By applying a new analytical expression to interpret the data,
quantitative estimates for both spin wave stiffness and damping are extracted
across a wide temperature range between 70 K and 250 K. We speculate that their
non-trivial temperature-dependencies arise due to the effects of magnetic
frustration arising from Mn magnetic moments, which is further reflected in
continuous variations of both exchange and Dzyaloshinskii-Moriya interactions.
