Go from VM to pot still

[scootr14]

I built a 2" copper VM hybrid. By hybrid I mean that I can break it down from 40" of packed/unpacked column, down to 20" of packed/unpacked column for pot still applications. I've been running running Rad's all bran with a 40" reflux with great success, but now I want to do a sweet feed run in pot still mode at 20", and I've evidently read to much so I've gotten myself confused. I understand to remove the packing, and make sure that my gate valve is open, but my question is, is it better to leave my double helix condenser in top and run it along with the liebig, or is it better to remove it and place a 2" cap ontop and run it only with the liebig condenser. I remember seeing someones set up like mine, but I can't seem to find it anymore. Thanks for all the great info on this site.