Particle scale height evolution of runs SI41-4-2-d, SI41-4-4-d, and SI41-4-2A-d, where the participating particles are τ_s = 10⁻⁴−10⁻¹. Left panel: simulation in a box of 0.2 × 0.2 H_g. Middle panel: evolution of the same system in a 0.4 × 0.4 H_g box, where the particle scale heights saturate to different values relative to the smaller box. Right panel: the total particle number was increased by a factor of four from the model in the left-most panel. In runs SI41-4-4-d and SI41-4-2A-d the particle subdisks do not saturate to a constant height within the simulation time.