When you harvest the plant and remove the top buds the plant will go into shock for a week or so. It will slowly get back to finishing the buds so if you have no other grow planned and can take your time to harvest then you can try to get the underbuds to finish completely. If another grow is planned it just waste time to let them finish. Look at the trichs. I harvest when the top trichs are about 10% clear, 60% cloudy and 30% amber or there about. The underbud at that point are usually about 50% clear/50% cloudy. It's a matter of timing as to when you cut but I look at whole plant development to decide.