Hi Nancy,
This is something that my firm does as internal training in R12! It's always useful to practice configuring Cost Transparency, especially when there are so many different routes that can be taken with a specific data set.
From my experience, we have a "Sandbox" environment, and, within that environment, we are able to create multiple projects. Having configured several of these practice projects in R12 myself, there have been no issues with launching the same components in separate projects. I've even configured the same data set multiple times as practice, and I've had no issues as long as the projects are distinct and separated!
I hope this helps!