the higher the wheel, the more the front ent will lift when the car pitches up. The lower the wheels the less lift, but it can unload the tires. You have to find the sweet spot that the car likes, with the equipment you have.
Try a hight of 4" see how it works, lower in 1/2" increments and see how the car responds.
wheelie bars are indeed primarily a safty device, but can be used to fine tune the car.