I believe one of the causes of the missing entities seen at the end of Day 71 is a bug in ChunkPositionFromTilePosition.
When this function computes the hadamard product, it's using chunkDimInMeters instead of tileSideInMeters & tileDepthInMeters. Since this function is only used currently by the world gen code (which is still operating on the concept of tiles), the abs values passed in are counts of tiles. By multiplying by chunkDim, I believe we're ending up with a single entity per chunk, and they're spread thinly across the world.