Hunting is almost always caused by control friction/binding somewhere and adding noseweight only slows it down, not fix it.
There may be other problems, too, that are obscuring the binding. There is nothing about an SV-11 design-wise that requires you to pile on noseweight to the point you have trouble maneuvering and the CG position should be very tolerant. I would strongly suggest that you measure everything for straightness and alignment, return to a baseline "bench trim" and then start over. But *for sure* check very carefully for any sort of binding, even the slightest rub anywhere will cause it.
Brett