Thanks for the question and for purchasing the toolkit! I double‑checked the docs.
The “wind effects” mentioned in the docs are implemented, but only for Terrain grass details (the built‑in grass / billboard details). Those use the G5WavingGrass shaders, which include a procedural wind/wave animation. Detail meshes (painted as meshes) use a different shader (G5TerrainDetail), and that shader doesn’t include any sway logic — so there’s no place to “enable” it right now.
You’re absolutely right that the docs don’t clarify where the effect applies; I’ll update the documentation to make it explicit that it applies to Terrain grass details, not mesh details.
If you’d like, I can implement sway in the mesh detail shader as well (so painted meshes move similarly). Just let me know and I can add it as a request.