Transport experiments on two-dimensional superconductors often yield direction-dependent transition temperatures, raising the question of whether such a “double-$T_c$” reflects a true thermodynamic splitting or a transport artifact. To establish a baseline, we study a minimal anisotropic phase-only Josephson-junction array in equilibrium and under resistively shunted junction dynamics with fluctuating twist boundary conditions. The equilibrium model exhibits a single Berezinskii-Kosterlitz-Thouless transition. Out of equilibrium, anisotropic Josephson couplings and anisotropic dissipation reshape the linear $R\text{−}T$ curves in a finite-size, finite-current crossover regime, so that curve-shape criteria such as Halperin-Nelson fits and fixed-resistance thresholds yield an apparent double-$T_c$. In contrast, critical-scaling criteria—the universal exponent $\alpha =3$ and dynamic finite-size scaling—remain consistent with the single $T_{\mathrm{BKT}}$. A robust splitting that persists in the nonlinear critical scaling, such as that recently reported at ${\mathrm{KTaO}}_3$ interfaces, therefore, points to physics beyond this clean anisotropic baseline.

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• BKT transition
• Helicity
• 2-dimensional systems
• Josephson junctions
• Superconductors