IMO, not a good idea, as the tapered down part of the seatpost isn't very long. Does it at least go past the threaded portion?
The minimum insertion for quill stems are about 2" and that seatpost doesn't have that.
so basically, while the idea is interesting, it needs a minor tweaking before it's safe.
I hear what you're saying and you're probably right, however it does reach far enough to be fully clamped by the adjustment lever. Admittedly, I would feel much better if the tapered portion were at least an inch longer.