Say you have a plaque design with multiple static components. Now you want to make several instances of that plaque with one component that's different on each plaque.
One way to do it would be to create a separate file for each plaque. But the problem is if you make a modification to the base plaque then you have to go back and modify each plaque.
The other way would be to have the base plaque and all one time use components in one file. This way if you make modifications to the base plaque you only have to do it one time.
The problem comes in when you start creating multiple Roughing and Finishing Toolpaths. You have to make sure only the base plaque and select one time component are active before recalculating each Roughing and Finishing Toolpath or the results will be a mess.
I hope this makes some sense.

I can't figure out a way to associate components to a specific Roughing and Finishing Toolpath.
Don't get too critical over the example, it's just an example....