We study the family of non-holomorphic complex iterations zn+1 = Kzng(Im(zn))+c, parameterized by K > 0 and a real-valued gate function g. We prove an exact Decoupling Lemma, derive a closed-form two-step stability boundary, and establish that the stable parameter-space area satisfies A(K)∼C(α,g0,R) K−γ with universal exponent determined by the vanishing order αof g at the operating point. This yields three universality classes: Class A (g(0) > 0, γ = 2), Class B (odd zero, γ = 1 with logarithmic correction, exact coefficient CB = 2R), and Class C (infinite-order zero, anomalous scaling A(K)∼2R/√ln K, exact coefficient CC = 2R). We verify the predicted exponent to 0.2% precision across eight functions spanning six independent scientific fields, including non-integer exponents (α= 1/2, γ = 4/3, verified to 0.14%; α = 3/4, γ = 8/7, verified to 0.08%) and a super-linear exponent (α = 2, γ = 1/2, verified to 0.01%). The formula γ = 2/(1 + α) is proved for 0 1 is proved with γ = 1/α and exact constant involving sin(π/α). The two cases join continuously at α = 1. An N-step extension establishes that the universality exponent γ is unchanged by replacing two-step escape with n-step escape. A new section characterises the fractal geometry of the stability set: cusp bifurcation near K ≈11, imaginary-axis displacement law Im(z∗)∼−ln K, and a sharp phase transition at K∗ ≈25 between power-law and exponential-collapse regimes, confirmed visually across the full parameter family.
Michael Bird (Sun,) studied this question.