For Generic Model Families and their derivative categories, this is dependent on whether the family is work plane-based or not. Work-plane based families will only show the limited range of views (as will only host-based families).
The video below outlines a method of leveraging out these extra views for work plane-based families. Please note this will not work for host-based families, such as wall, floor or face-based. Essentially, the steps are as follows
- Place the component into the 3D model onto its host face
- Right click the component and 'Edit Family'.
- In the Family Category Parameters, uncheck the 'Work Plane-Based' box
- Reload into the project
- Place the Legend Components into the Legend with the required extra views
- Re-edit the family, Re-check the 'Work Plane-Based' box and re-load
The Revit Option bar dropdown box will read the incorrect view, but the properties for the Legend Component will show the extra view as correct. Revit now retains these views
Please feel free to feedback if any issues arise, as this is a recent discovery. As far as I can tell, things are sound in the method, but you never know.