A chunk's meshes are in the scene and renderable. Fires from the same place
for synchronous and worker builds, so chunkWorker: true doesn't change
when (relative to the geometry existing) consumers hear about it — only how
many frames later. Use it to place props, spawn decorations, or drive a
"world loading" indicator.
A chunk's meshes have been removed from the scene and disposed — because it
streamed out of range, or because dispose() / setMap() tore everything
down. Anything you parented to that chunk's region should go now.
Events emitted by ChunkManager.events.