This arXiv preprint (abs/2606.00565, May 2026) demonstrates that disordered silica microsphere coatings achieve robust passive daytime radiative cooling across particle diameters of 2–8 µm once in the multiple-scattering regime. Experimental methods included spectral reflectance measurements and outdoor steady-state temperature tests under clear-sky conditions, revealing nearly identical net cooling performance despite variations in single-particle scattering. Sample size details are not reported, limiting statistical power assessment. As a preprint, the work lacks peer review and long-term weathering data. The finding decouples optical performance from size, allowing optimization for surface chemistry and adhesion—factors often overlooked in policy discussions of urban heat islands. This aligns with earlier peer-reviewed results in Mandal et al. (Science 2018) on porous polymer coatings and Li et al. (Nature Sustainability 2023) on scalable paint formulations, which showed 5–10 °C sub-ambient cooling but emphasized fabrication constraints. The new results suggest collective diffusive transport dominates, enabling broader material functionalizability for real-world building integration and reduced air-conditioning demand.