On Mac OSX there is a really neat feature: the ability to create an “aggregate audio device” that chains multiple soundcards into a single virtual device. This essentially lets you expand your inputs and outputs indefinitely. You can do a similar thing with Jack on Linux and with ASIO4All on Windows, although with variable levels of success.
My question is: where is the hardware device that will do this? It would be amazing to have a thunderbolt or USB C device that could aggregate any class-compliant audio interface device into a single interface. Please someone make this.