That the H4 can get down to 2.0-3.9 W idle puts it into Raspberry Pi 4/5 levels of idle power consumption, which is extremely impressive. I assume they used the minimum sized RAM (8 GB) and eMMC instead of a NVMe drive.
I'm really surprised by those idle power draw figures. Most N100/N95 mini PCs idle at around 10 watts.
That looks like a pretty neat piece of kit for a modest NAS