You can sweep out of a single plane with Revit, but you have to model "helper objects" and use Pick Path to do it. It would be nice to be able to just draw in the path rather than having to model these helper objects in. (And no, I don't have a suggestion on how the tool would work!)
I place these helper in a subcategory so they can be turned off, and/or an off-by-default workset.