I assume you are talking safer in terms of aircraft performance.
The worst case scenaro should be looked at, one engine inoperative, the climb gradients required to be met are the same for both weights.
The V1 speed is like a gate where with one engine inoperative, and the energy the aircraft has at the time it can successfully meet its climb gradient requirements.
Assuming you are talking about a runway that has a ASDR limit at 7000 kg. At a lower weight V1 is less, and the point you rotate is closer to the start of the takeoff roll. The climb gradient performance is based upon the point you lift off from the runway, so the aircraft may have and additional altitude by the time it pass the rotation point for the 120 knots. More ground clearance is better in my view.
Increasing your V1 in a 1900 is only really useful in conditions where microbursts, turbulance, ice formation is expected. You are far safer to delay your takeoff and not enter the conditions as the two engine climb performace may not exceed the conditions encounted.