Reduce cube size by creating views within Scenarios

Summary: I want to know if a capability exists that would keep cube sizes smaller by reducing redundant data

Content (required): My client has many scenarios that are complete with full year data (12 periods, per year) and these scenarios are a blend of actuals and forecasts. Instead of having multiple scenarios with several months of actuals repeated, is there a way to configure a scenario so that instead of duplicating the intersection, it would provide a view into the Actual scenario for a set of defined periods within that scenario?

The value I see here is in application size, but I could be wrong. This is something I'd be interested in learning more about across all EPM Business Processes.