First of all, however, something needs to be said regarding maximum protein assimilation theories. That being, there is no magic number of grams of protein that the body can handle in a given time frame. It is governed by a few factors, all of which are variable from person-to-person and time-to-time. Here are are some:
(1) Current levels of free amino acid pool population. The body carries a certain amount of amino acids in the bloodstream at any given moment. This is sometimes called a "nitrogen balance," although it could be argued that this is actually a misnomer. When the amino pool reaches undesirably low levels, it will have to pull amino acids from either stored body tissue or food. At times of low amino pool levels (e.g. post-workout, post-fasting), the body's ability to digest and assimilate a greater amount of protein is heightened.
(2) Available protease and pepsin play roles in how readily a protein can be uptaken into the body. Insufficient free enzyme levels will result in poor digestion. This is a minor limiting factor, however, unless a tremendous amount of easily digested protein is consumed in one sitting.
(3) The type of protein, contents of the stomach, and other things consumed along with the protein will all factor into how rapidly the protein is digested. A protein that populates the amino acid pool very rapidly (e.g. whey hydrolysate), taken on an empty stomach, with nothing else but high-gly carbs to facilitate an insulin response, will be best suited for rapid amino pool population applications. This would be basically PWO or upon waking in the morning. A slow-digesting protein (e.g. micellar casein), taken with lots of fat and fiber not too long after a prior meal would take a very long time to dump amino acids into the bloodstream. We could be talking about anywhere from 6-12 hours. It would clearly be conceivable that consuming 90g of protein in the first scenario would lead to much more amino "wasting" than the second.