Currently, even with Revit 2024, there are no options to choose or define the sheet size for exporting the Revit Sheets to DWG. The default size by the printer is chosen for the Layout in AutoCAD even though Sheet sizes are defined in the title block. We have external add-ins to achieve this, but this setup should be added and defined as part of the default export setting from Revit, just like Exporting PDFs that has the option to choose the sheet size.