The spin up/down cycle is a problem for external drives too(they have vibration negation through arm lock when the drive is moved), these backup disks where meant to be used like 5 times a day to copy data but when they are run 24/7 the up/down cycle goes up a lot and so they become a problem. Regarding the heat issue, once the hdd(no matter what drive other than enterprise ones) goes over 50c you can expect to drive failure/corruption/error.
The error code from hdparm is because the chain of command is lik usb to uas to scsi to sat to sata and along the way some of the controller was not designed to properly respond to the other. It happens in almost 90% of the drives manufacture(usb disk controllers). So the best option is to to sdparm to do the same.
Hope this helps
Regards
