UV setup implementation for the optical depth and TP profile calculations. Left panel: optical depth profile for a 0.1% H₂O atmosphere irradiated by the average flux from AU Mic, representing a flaring young M dwarf reference. As before, the colour map shows varying τ values across the atmospheres with light blue line as τ ~ 1. Right panel: comparison of T-P profiles, including the UV setup profiles for the 0.1% H₂O atmosphere under quiescent and flare-averaged fluxes (dashed orange and red lines, respectively); the T-P profile based on a wavelength grid used throughout this study (solid blue line); the same atmosphere heated by an additional 400K from the interior (solid green line, the light green shadowed area denotes convectively unstable layers); and a mini-Neptune T-P profile with surface gravity comparable to Earth from Kempton et al. 2023 (solid light blue line).