Average integrated energy flux for SN 2023ixf as predicted by the SN 1993J model from Tatischeff (2009) compared with integrated energy flux upper limits from the Fermi-LAT (coloured markers). Fluxes and limits are integrated starting at T₀ + 1 d. We assume u_w = 100 km s⁻¹, in line with spectroscopic results (Smith et al. 2023). Radio/millimetre (230 GHz) lower limits from Berger et al. (2023, u_w = 115 km s⁻¹) for free-free absorption assuming different electron temperatures T_e are also displayed. Finally, the prediction derived from X-ray absorption features in Grefenstette et al. (2023, marginally consistent with millimetre-wavelength limits) is shown for completeness.