The safest range is usually somewhere between the middle of the manufacturer's specified range to the forward most point, the one closest to the leading edge. I would steer clear of the rear location until I knew the plane.

On a scale plane, I would guess that anywhere would be fine, especially since the planes is aimed at the sport flier and since I have heard that Kyosho is a reputable manufacturer.

I would still put the CG forward for the first test flight.