Well you can't ignore pathnames on some files / folders and not on others so I don't really see how the column would help.
With preserve full pathnames off, if you drag a file to the source box it'll be in the root. If you drag a folder it'll be in the root (unless it's the ONLY thing in the source box in which case that's optional).
With preserve full pathnames on that files / folders you drag over will be exactly as they are on your hdd - with only the drive letter being different.