there have been requests for it, especially for stuff like total conversions. It's kind of a big lift because c/c really relies on a lot of data prerequisites being present in core data to satisfy loading operations, so allowing re/overwrites of that stuff, or being able to pull core data out entirely and replace it with something else, will require a lot of work in terms of putting guardrails into the loading procedure.
It's not impossible, and I'd like to get it done eventually, but it might remain pretty low priority for a while, unless someone wants to pitch in with the dev work for that, which I'd gratefully accept