So, it sounds like the best advice to OP is to create another 'home' account for their son, on the same device, which won't be monitored or affected by anything the school does.
The son can decide which account to log into based on what they plan to do that day.
Probably better to login (or not) to the chrome OS device as a personal account, and then login in the browser (private mode perhaps?) to the school account to do the classroom stuff. I don't think logging in to the school account in Chrome the browser will trigger the same behavior as logging in to the school account in Chrome the OS.
> The son can decide which account to log into based on what they plan to do that day.
You can log into multiple accounts at once on a Chromebook. ctrl + alt + `.` lets you switch between workspaces across accounts, and you can right click windows to move them across workspaces. I'm doing this right now so I can post on HN from my personal account while I code for work.
The son can decide which account to log into based on what they plan to do that day.