PAH 11.3/7.7 μm versus PAH 6.2/7.7 μm diagnostic plot for the five regions of interest: full Ch 1A mosaic (red circle), nucleus (magenta diamond), circumnuclear region (violet hexagon), PAH ring (yellow cross), and PAH-deficient region (green star). The large uncertainty on the nuclear PAH 6.2/7.7 μm ratio and the upper limit on 11.3/7.7 μm result from partial detection of the 6.2 and 7.7 μm features (Appendix C). Grey symbols show CAFE-derived ratios (Appendix D). Uncertainties on the CAFE ratios, which span nearly the full x-range of the figure while remaining close to the SPIRIT y-axis values, were omitted for clarity. We overlay the grids of Rigopoulou et al. (2021) for neutral PAHs (grey; illuminated by 0.5 − 10³ ISRF), and partially ionized PAHs (25 − 75%; blue; 1 ISRF). PAH size increases along the x-axis (right to left) with the number of carbon atoms (N_C) while the ionized fraction increases along the y-axis (top to bottom). The dashed black and blue curves mark the neutral and ionized PAH limits from Draine & Li (2001), for 1 ISRF. For comparison, we include PAH ratios for Seyfert nuclei from Diamond-Stanic & Rieke (2010, circles; filled symbols indicate high H₂/PAH luminosity ratios); and from García-Bernete et al. (2022a, 2024), shown as squares. Triangles denote outflow regions in the same systems. Plus symbols represent the three regions in the central kpc of the Seyfert 2 ESO 137-G034 (Zhang et al. 2024). For clarity, we omit the uncertainties associated with literature ratios.