The procedure specified by the system setting "ImpersonationProcedure" is used when it is desired for other users than administrators to be able to impersonate users.
This feature was designed to be used by super users when testing user role related issues in stage instances. It was not designed to be a reliable way of handling end users with multiple roles. This can lead to unexpected behavior as user impersonation is shared between all browser windows in a session without visual cues for the user.
Redirects to the impersonated user's start page after switching users.
By default the user remains on the same menu item after impersonation. This can cause problems if the impersonated user has lower permissions than the impersonating user as they may not be allowed to view the open menu item. It's recommended to redirect to the impersonated user's start page to avoid this.