Users following the installation instructions end up without ethernet as module sunxi-gmac doesn't get auto-loaded.
Providing an appropriate file /etc/modules-load.d/*.conf within the image doesn't make sense, imo, as sunxi-gmac is part of linux-sunxi kernel only and a file like this triggers failure of systemd-modules-load.service running mainline kernel.
But a brief note would make sense.
Both in "Install to a micro SD card - 6" and "Install to USB or SATA - 7" sync is stated after unmounting the respective storage device.