Absolute values of the O₂–O₃ relationship at all O₂ and CH₄ levels modeled for planets around the Sun (left) and M5V (right) hosts. O₂ levels of 0.1%, 1%, 10%, and 100% PAL are marked with vertical dashed lines to enable easier comparison with Fig. 3. This figure highlights the stark difference in how CH₄ impacts the O₂–O₃ relationship differently for hotter and cooler host stars, due primarily to the amount of UV flux arriving at the planet. For hotter hosts the higher UV flux allows more efficient conversion of CH₄ into H₂O and then HO_x compared to the lower UV flux of M5V host. Full O₂–O₃ relationships of all hosts including comparisons to Kozakis et al. (2025) are located in Appendix A.