The reason for recommending split-dosing during the day is based on the half-life of around 9 hours for oral winny. Bill's thought is an intriguing one, however I am not sure it is really founded. For example, acetaminophen (Tylenol) is extremely toxic to the liver, very much in a dose-dependent fashion. You can safely take 650mg every 6 hours for 24 hours (for a total of 2400mg in 24 hours), but a dose of 2600mg all at once would be rather hepatotoxic.
I'd have to see more evidence presented on this.