i would also like to suggest, perhaps, using mouse gestures along with directory opus. it makes things so much easier to draw a 'd' with the right mouse button and be taken to the root of d drive, or whatever you configured that gessture to invoke.
i think that a nice compromise could be to use strokeit mouse gesture program and tell it that if you hold right-click and move the mouse it the up direction (only a few pixels is enough) to go up a directory. arguably, this is fast as dbl-click on whitespace if you move the mouse only a few pixels up instead of doing like i used to and moving my mouse waaaaaaay up; strokeit is surprisingly sensitive! this would also convey especial convenience when the lister is a long display mode and there's hardly a free space to click, one just has to, wherever the mouse currently is, right click/slide up, or left for back, or right for forward, or whatever your mind can imagine! also, strokeit needn't be installed and can be run just fine from a usb.
but, i'm not sure if this is what OP wants?