I am unsure as to whether this is the case with other Jamf products, however I can confirm that the QR code in the Jamf Student App does indeed work for parents to control their children's devices in Jamf School. But I do see your reasoning, what is there to prevent another student or they themselves from scanning their QR code and taking control over their or someone else's device? In Jamf School, you do have a bit of control over the use of the Jamf Parent App in that you can restrict it to a certain time of a week day and all the time on weekends, you can also control it via geographic location. In order for the parent feature to work, a user group called "parents" needs to be created with allowed access to the Jamf Parent feature and Jamf Parent also needs to be enabled. As I have teachers that are also parents and parents that live at the school, I have had to set mine up less restrictively and monitor the members of the group from time to time.
