The effect of ¹⁴N(p, γ)¹⁵O reaction rate (the default JINA REACLIB, solid gray lines vs. the NACRE rate, dashed green lines) across metallicity (Z = 0.014, Z = 0.004, and Z = 0.0014, in the left, middle, and right columns, respectively) and overshooting (no overshoot and core and envelope overshoot enabled, in the top and bottom rows, respectively) scenarios. Fiducial hot IS strip is overplotted for reference.