Let's assume the lifter preload is some where between .xxx preload and not bottomed out. Let's also assume the lifter doesnt bleed down and the valve train doesnt go into false motion. In this case the amount of preload means absolutely nothing. Now if it bleeds extra preload may keep the valve train clearances close enough so the valve drain doesn't gain enough lash to fall apart. If the valve train is unstable to some degree minimal preload will limit the amount of positive lash in the valve train. If you have both issues you have a problem. Other than this there is no magic. As usual it's a case of over thinking.. My 2 cents
Doug