Figs. S1.11-S1.18 plot for each of the models the thermal conductivity as a function of temperature obtained using a series of sampling meshes. Tables S1.3-S1.10 compare 𝜅 latt values at 𝑇 = 300 and 600 K on each of the meshes tested to the chosen converged meshes. For the pristine and filled models based on the conventional cell, the thermal conductivities calculated using the 9 × 9 × 9 sampling meshes differ by at most 2.7 % compared to those calculates using larger 11 × 11 × 11 meshes. We note in passing that for most of the models sampling meshes with an odd number of subdivisions appear to converge faster than "even" meshes, which we attribute to a flattening of the acoustic mode dispersion close to the zone boundary (c.f. Fig. in the text).