To add  a little complexity to the FC2K generated wrappers would be to add an optional new port (triggered by a choice in the GUI) which would take as input 0 or 1.

• In the case of a 1, the physics code would be called in the usual way, but the result would also be "remembered" internally by the wrapper.
• In the case of a 0, the physics code would not be called, but the result remembered by the wrapper would be replayed.

This would allow for cleaner, less complicated workflows and a great deal more flexibility in changing the frequency with which codes are called.