Completely understandable my suggestions were a bit less of what you should do and more of what should be done for integration into trunk. Your code works well, obviously accomplishes what you need, and doesn't break existing stuff all which are good. The downside is anyone trying to understand portaudio and use portaudio now has two very different interfaces for doing so depending on what they want to do. In addition any code that wants to take advantage of multi-channel portaudio has to be rewritten.
And may be that's the reason writing a mod_portaudio2 would make more sense where we would not be worried about breaking current code. There was a guy back in January that mentioned having something ready and about to release, but I could not find anything in the tree. - Moy