If you're concerned about one or two bits being toggled, a 512-bit hash will merely increase the chance of bit errors; on a noisy medium, using such a big "checksum" will BOTH detect and cause a high number of packet faults.

Nice to see a manufacturer producing a 2018 netbook. Netbooks were very useful devices. A lot of people around me used to have netbooks. Basically everyone who needs to produce (not just consume) on the go. Think students. I don't see how netbook concept should be dead. And they are fine qualitywise. You get what you pay for. They have awesome bang for the buck.

Previously owned devices sales next? If they are including blacklisting code like this their software simply cannot be trusted.

No. There is a simple explanation too. Once a valid sale happens ownership changes. They still own these devices, because they were stolen. That means they can do whatever they please, the devices are still theirs.

Ownership change doesn't magically disable their remote control, though.

Unlikely it'd run into all sorts of first sale doctrine issues if they blocked resale of hardware components.

That's the case with any device with non-free firmware.