Since you will exchange your Nichkan Gohonzon sooner or later, might as well exchange it now for a Nichiren Gohonzon

Send me your Nichikan Gohonzon for respectful disposal and I will send you a Nichiren Gohonzon for free. Why wait five or ten years until SGI tells you that they are switching to a copy of Nichiren inscribed Gohonzon? THEN you will throw out the Nichikan Gohonzon anyway while paying for one of SGI's inferior quality copies. Since you will throw it out all the same, it is better that you throw it out now than later. Better now to receive the boundless benefits of the Law!