And to complete the answer I received to maybe help someone else in the future, it looks like to achieve the barreled roof that is a single click operation in the dormer tool, it requires some manual roof edits to achieve as a wall dormer.
https://www.chiefarchitect.com/support/article/KB-00649/creating-a-curved-barrel-roof.html
https://www.chiefarchitect.com/videos/watch/746/drawing-curved-and-barrel-roofs.html