I think that you'll all just have to find your own balance to figure out what works best for you and your baby. In my experience I had an extreme case of oversupply. At the beginning of trying to get it under control I was actually doing 12 hour blocks for the first couple days, then I went to six hour blocks, then three hour blocks after a few weeks. Now, at 9 months, I simply switch sides each nursing and my supply is still more than ample. You just have to listen to your body and your baby, and find the right balance for you.
I liked what this lactation consultant said here:
"If she hasn't gotten to the bottom of the barrel - if that side isn't nice and soft when she finishes - use it again next time. Here's where your intuition comes in. You may find that sticking to one side for a couple hours is all it takes. And after your supply has settled down to match her needs and things are running smoothly, you'll largely forget this notion... although you often see nursing mothers hefting one side and then the other to decide which they want to use. If your "oversupply" has been dramatic, or your baby is really fussy, you may find you need to spend 4 to 6 hours on one side before using the other. What's happening to the other side in the meantime? The sense of over-fullness is sending a message to cut back on production, which is what you want. If you're too overfull, you can nurse or express on that side just enough to relieve it somewhat, then go back to the side you're trying to soften completely.
These sound like rules, but they're actually just temporary rules to help you get past those two initial rules that probably started the problem - making a point of switching sides, and spacing nursings to two hours or more.
As your supply settles down, you may worry that you've "lost your milk." You may be so accustomed to heavy breasts dripping and spraying, and to seeing your child splutter, that a quiet, calm nursing from soft breasts feels "wrong." But you'll probably notice that those diapers are still very wet, and that your child nurses contentedly, with a relaxed and comfortable body, letting go gently when she's full or dozing peacefully at breast. Those are all signs of an ample - but not overfull - milk supply. If she wants to increase your supply further, all she has to do is ask to nurse more often, or fuss to go to Side Two after Side One is completely soft. Trust her to know her own needs, and trust your body to respond appropriately.
Cutting down on an oversupply is usually a simple, straightforward process, and you should begin to see a happier baby within a few days."