I'm wrong because I stated that you can't put a tag on exactly how much protein can be absorbed in one sitting? Wow, imagine that. I can't remember the last time someone was wrong for saying one bodily process involving many individual processes varies from person to person.
And I didn't say that all the protein would be absorbed. Yes, there is a certain limit that is individual to each person as to how much protein can be absorbed for muscle-building or muscle-preserving purposes. What I was saying is that 30g is not necessarily the limit. And whatever protein your body does not absorbed will be likely used for fuel. That's what I was addressing when I was saying why it's important to space it out so your body won't have to make immediate use of the protein. Take casein for example; you can take in a whole lot of it at one type and reap the benefits of it better than you could something like whey. Casein forms into a solid ball and is then digested/used I think for the next 6 hours. Whey is digested almost immediately, so in consuming large amounts of whey at one time you run the risk of burning too much of it for energy and not maintaining a positive nitrogen balance.
I think the incomplete proteins you're referring to are those found in beans, which includes soy which, even isolated, is still incomplete I believe (though I could be wrong). They're still gonna absorb, but they aren't optimal for muscle-building or muscle-preserving purposes.