Zoom-in view of the central panel of Fig. 7. We use a red curve to highlight the bottom limit of the blue interval, otherwise the narrowness of the spikes makes them invisible (the width of spike d is Δλ ≈ 10⁻¹⁴). This graph can be compared to Fig. 3 of Saillenfest et al. (2021), where such level of fine tuning is not shown due to its questionable physical relevance. See Appendix B for examples of trajectories.