Why does the highres.fix downsample even when resolution is divisible by 64?

[Taikakim]

For an example, 2,5x scaling on a 512x640 image would be 1280x1600. Still during the process the init image gets downsampled to 320x400. Why is this? This is using the LDSR upscaler. And actually even now with a plain 2x resolution, the init is downscaled to half.