Results for the average front position and front roughness are provided in Fig. 12. The time evolution of the average front position turns out to be of the expected power-law form, h (t) ∼ t δ , with δ 0.58. Hence, the average velocity of the front decays with time, as expected due to the time-decreasing KPZ coupling in Eq. (16). However, the amplitude of front fluctuations does increase with time as indicated by the powerlaw behavior of the roughness, w(t) ∼ t β with β 0.35, seen in Fig. 12. For reference, recall that for the 1D KPZ universality class one has β KPZ = 1/3 [15][16][17]. However, we believe closeness of the growth exponent to the KPZ value is coincidental, as it does not occur for other exponents. This is confirmed by Fig. 13, which shows the structure factor S(k, t) for different times. Note that the large-k behavior of the various curves is time-independent and exhibits no anomalous shift with time, in contrast with the kMC results shown e.g. in Fig. 9. Hence, scaling behavior is standard Family-Vicsek type for Eq. (16), as further confirmed by the **data** collapse performed in Fig. 13(b) according to Eq. (12), whereby the u-independent behavior obtained for large u in the numerical scaling function implies α = α loc 1. Hence, neither α = 1 nor the z 2.65 value implied by the collapse, are anywhere close to the 1D KPZ values (α KPZ = 1/2 and z KPZ = 3/2), in spite of the fact that their ratio β = α/z 0.37 is not so far from β KPZ .