900 or 2000? Your title is 2000 and your post is 900.
The 900 has a sound card in it so you can use it as a standalone mixer. It just replaces your external sound card and you select external mixer in TP. Hence, no mixer section in TP. The 900 will not be mapped out to the mixer, why would you want to when you use the internal mixer when you have a 900? But if you really wanted to, you could.
Not really sure what you mean other than that. Your post is confusing to me. If you need more info, please be a little more clear :)
Cheers