The tension on the spring doesn't affect the characteristics of the spring as far as compressibility, all it affects is the ride height. The looser the springs, the lower the front end sits. The lower the front, the lower the COG. The lower the COG, the flatter it turns.
You CAN affect the compression characteristics of the front suspension harder in one way: STRAP IT DOWN. If you increase the preload, but strap it into a lower ride height, you will make the ride somewhat harsh, but it should make the ride VERY stable.