Location of CofG in the nose like this is a flight dynamics design issue. Just as gypsymoth says, increasing the positive number will move the CofG backwards. Usually it doesn't have an effect on nose-down, which can be addressed by adjusting the cruise_lift_scalar parameter in [flight_tuning] (lowering the number, often below 1 to 0.9 or lower, will raise the nose as the winglift is incrementally decreased).
A CofG that's too far forward will have the effect of making the plane fly like a shuttlecock; pitching, rolling and yawing around a point that's artificially too far forward. Likewise for the tail if it's too far back. It can be noticeable on rotation or landing where the main wheels can partially disappear into the tarmac as the plane pitches around the nose rather than normal CofG which is around a 0.3 wing chord, waterline, centreline.
