Thermal and non-thermal emission from a variable outflow – internal shock framework: impact of the outflow parameters. Starting from the reference case shown in Fig. 2 (with a redshift z = 1) we first change the thermal fraction ϵ_th to 0.3 (top left panel) and 0.003 (bottom left); then the isotropic power Ė_iso to 10⁵⁴  erg  s^-1 (top middle) and 10⁵²  erg  s^-1 (bottom middle); and finally the Lorentz factor is multiplied (top right) and divided (bottom right) by a factor of 2. Each time we vary a parameter, all the others keep the value corresponding to the reference case.