A composite wood product in accordance with a particular embodiment of the present technology includes a composite substrate and a sealant disposed within a surface portion of the substrate. The substrate includes wood and a binder. The sealant includes photoresponsive molecules present within the surface portion of the substrate at an average concentration greater than 1000 parts per million. In response to a 120-day exposure at 7 inches separation distance to a UV lamp with a UVA (315-400 nm) output of 13.6 W and a UVB (280-315 nm) output of 3.0 W, a CIELab b* value of the substrate decreases by a first amount, a CIELab b* value of the sealant increases by a second amount, and a CIELab b* value of the overall wood product decreases by an amount less than the first amount, increases by an amount less than the second amount, or is unchanged.