Perhaps some enterprising group could build a motor-driven turntable that slowly rotates the top of the pedestal on which the cap rests -- so that all sides are made visible. (Inexpensive clock-drive motors are readily available...)
Similarly, a public (and publicised) donation of a new interpretive placard to go under the cap-- with a "compass rose" to indicate the direcion each side faces atop the monument, and returning to the 2000 wording -- could be made and presented.
Seems to me that, with a large public outcry, (and with no dollar outlay on their part) the NPS would be forced to accept and use the donated "interpretive display aids"... .
Opportunity for some effective activism by a few, ingenious and dedicated FReepers?...