I  work in an educational environment. We have roughly 1000 student Windows 7/10 machines in an Active Directory environment. We are running into security issues where students use a shared AD login ("Room100Lab") but sing into the Google Chrome browser using individual Google Accounts.
I tested the ephemeral mode as a computer policy and it works as expected. But I want students and/or faculty who log-in to Windows using their own individual accounts to work in the normal environment (not ephemeral mode). I want shared accounts to work in ephemeral mode. The same settings are available as a "User" policy rather than a "Computer" policy. I accompllish this by enabling loopback policies in AD, setting the ephemeral mode to "enabled" under the user settings, and permitting the "Apply Group Policy" security setting only for the shared user accounts.
This works partly. When the Chrome browser is closed and re-opened, the user who was previously logged into Chrome is still displayed in the title bar box. However, Google content is not available (Gmail, Drive, etc.). But another user can't sign-in without first going to settings and disconnecting the account being displayed.
Is there a way, applied as a user policy setting, to completely disconnect the account from Chrome when the browser is closed. Once again, this works fine when applied as a computer setting, but there's no way to specify who the policy should be applied to.

Thanks,  ...Kurt