  In this paper we explore possible extensions of Interacting Dark Energy
cosmologies, where Dark Energy and Dark Matter interact non-gravitationally
with one another. In particular, we focus on the neutrino sector, analyzing the
effect of both neutrino masses and the effective number of neutrino species. We
consider the Planck 2018 legacy release data combined with several other
cosmological probes, finding no evidence for new physics in the dark radiation
sector. The current neutrino constraints from cosmology should be therefore
regarded as robust, as they are not strongly dependent on the dark sector
physics, once all the available observations are combined. Namely, we find a
total neutrino mass $M_\nu<0.15$ eV and a number of effective relativistic
degrees of freedom of $N_{\rm eff}=3.03^{+0.33}_{-0.33}$, both at 95\% CL,
which are close to those obtained within the $\Lambda$CDM cosmology,
$M_\nu<0.12$ eV and $N_{\rm eff}=3.00^{+0.36}_{-0.35}$ for the same data
combination.
