one of the biggest shortcomings of Cubase is its inability to aggregate multiple interfaces for an expanded number of inputs/ outputs. This is causing us to jump through various hoops and loops to connect interfaces to work together. This makes choosing hardware and upgrading a total nightmare.
Make Cubase be able to aggregate and fully utilize all interfaces that are connected to a computer as if it were a single interface. It is the year 2019: cars are driving by themselves, robots are doing summersaults and yet we are stuck with a single interface/ driver within Cubase. Come on, Steinberg!
ASIO4ALL is a great driver that does this successfully, but unfortunately you made your hardware drivers to only have a stereo pair of inputs and a stereo pair of output recognized by ASIO4ALL.