I would like to see the study and make sure it's peak levels, and not peak percentages. As far as I'm aware, all cannabinoids tend to peak at around the same time.
Unless you're making edibles or topicals for 'just' the CBD, you're going to want to harvest any strain when it's 'ripe.' This will give you cannabis which lasts the longest, is able to be the maximum potency for the strain, and have the most complex terpene profile. It will not be sleepy in any way (unless it's naturally a heavily CBN rich strain).
Early cut will shorten the time of effect, increase the amount needed for the same effect, reduce yield and have a not-quite full expression of the terpenes. A rather large triple whammy. Oh yeah, it will be a bit speedier and more upbeat. Whee.