Creating Private appointments as a Delegate

As a delegate for my manager, I sometimes also need to create Private Appointments. However, I do not have the permissions to see any details of his existing Private Appointments.

But when I’ve been set up as a Delegate without permissions to see Private items, the button to mark an appointment as Private is grayed out as well.

Is there a way to be granted this level of permissions without losing the option to mark appointments as Private?