The success of benign termination scenarios for controlled RE mitigation depends strongly on the properties of the cold, weakly ionised plasma coexisting with the RE beam, referred to as the companion plasma. In previous work, the edge plasma code SOLPS-ITER was applied to model companion plasma particle, momentum, and energy balance during the flattop phase of TCV benign termination experiments. These simulations demonstrated the code’s capability to reproduce key experimental trends, such as the non-monotonic dependence of the average companion plasma density on neutral gas pressure, $\langle n_e \rangle (p_N)$. Building on these results, the present work extends the modelling in two directions. Impurities ($Ne$ and $Ar$) are included in TCV simulations to assess their impact on recombination properties and energy balance. In parallel, dedicated power scans, combined with systematic comparison to experimental data, are used to quantify the fraction of RE beam energy absorbed by the companion plasma and how this varies with $p_N$. This study also presents the first SOLPS-ITER simulations of companion plasma recombination in ASDEX Upgrade. For the first time, consistent trends in companion plasma density and temperature as a function of gas pressure are observed in a machine other than TCV, strengthening the confidence in the modelling framework and its applicability for predicting RE mitigation requirements in future devices.