One more thing I'd like to add: 

Aside from the lifestyle/reality issues, if you have a young child who is on a very small total amount of HC/day, it may not be practical to go to 4 doses/day, anyway.  For eg., if the total daily dose is only 5 mgs., it is not really practical to split one tablet into 4 pieces---with one proportionately much bigger than the other 3.  Quality control would go right out the window, and the point of carefully titrating the doses to mimic circadian rhythm would be completely lost.  The problem is even more acute if the daily dose is even smaller.  Given all the trade-offs, it would probably make more sense to stick with 3 doses during normal, waking hours, in those situations. 

I know everyone is eager to do whatever is necessary to maximize treatment for their children.  But, in a forum such as this, it is very easy, I think, to take something out of context and place emphasis on the wrong issue.  So, I would just caution everyone to please, just tread carefully!