Try this method. Loosen pinch bolts. Tighten preload bolt to limp wristed finger tight. Tighten pinch bolts moderately. Check for play in the bb. Repeat loosening the pinch bolts when you readjust the preload. Keep going till the obvious play disappears. Once obvious play has disappeared, tighten the preload cap a further quarter turn.
This method means the final quarter turn will remove any tiny micro play you can't feel by hand. However it will mean you can only over tighten by no more than a quarter turn, which won't cause damage.