In fact, InitDisk requires you to remove and reinsert the USB to prove that it is removable. @Steve doesn't want to be responsible for accidentally formatting a non-removable disk.Nope! InitDisk is for removable drives, e.g. USB sticks. It is not for fixed drives such as these.
I would expect InitDisk to "see" these driives as fixed and not process them.
I've used the same cable(s) for all my tests and those that failed I tried a second time by swapping the drive/cable to see if that repeat and to eliminate the cable variable.Your logs show SATA errors. Could that suggest a faulty cable or port?