ABZ lets you choose the default drive and folder for unraring. However, sometimes my default drive is out of disk space. And sometimes I prefer to extract some rar sets to different drives/partitions.
My suggestion is to add an option to set the drive (and possibly folder) for each RAR set individually. A command in the right-click menu would probably work best.
BTW, excellent program! I've been using it for a couple of days, around the clock. Works very smoothly. Many thanks!