osage, are you talking about just plugging it, as usual, and then tapering the plugged end? Or are you saying to have the hardwood dowel protruding from the end of the shaft, and to taper that. Either way (in my head) the shaft behind the head will still be a larger diameter than the ferrule. Is this a problem?
I'm seriously considering trying ionians method of splicing both ends. Really chaps me to get a shaft nice and straight and then have it split when drilling out the end or inserting the plug. The splicing seems a little more fool proof if you use the right set up.