My understanding is that any DAW hosting the Motif XS rack VSTi must have the DAW's audio driver preferences set to use the FW16 (Windows 7 in my case) ASIO driver. Is that understanding correct? In other words, can the VSTi connect to the XS-rack (via FW16 driver) independent of the connection between the DAW hosting the plugin (Live 9 in my case) and its ASIO audio driver connection (not the FW16 driver)? Of course I'm inclined to think my understanding is correct, that VST instruments/effects are absolutely dependent on their host application's audio driver preference setting. But maybe you can help set me straight in this case?
I'm pretty sure Max4Live will allow me to customize a similar solution. But there's a big learning curve along that route. There's also the Rewire route. But that requires a whole other DAW (latency path) running on the same bare metal CPU just to be a "rewire channel mapper" from FW16 audio to rewire (and back).