Currently, Multi-Category Schedules cannot schedule System Families. Consider the highly useful situation where you want to Schedule:
- Keynote (from Type)
- Description (from Type)
- Type Mark (from Type)
... and you want to create this schedule across all of the elements in the entire project. This would be immensely powerful for model quality checking and also creating a unified, live project item code schedule. But it is currently impossible in normal Revit. It can be done with other tools like Dynamo, but these do not reference the model live and thus the information would need to be continually refreshed in that workaround.
We need to empower Multi-Category schedules to be truly multicategory, where they can reference at least the consistent Type parameters (shown above) from every Category.
The image below shows an example of how many different schedules are currently required just to accomplish the above for an Architectural model:
How much better it would be to make Multi-Category Schedules true to their name.