the last week I see a slowing in growth & swelling (weeks 6 & 7 are the peak weeks IMO)...
you do have a good point though.
a cool thing about hydro is if you choose to ustilize a flushing agent (Clearex, Final Phase, etc) you can push your plants as hard as you can and then flush w the agent per the label for 3 days and you should be okay.
the longer flush though better chance of having the plant utilize all the built up nutes.