[quotePost id=117802]But WAIT - it gets worse.

Every time you enter the 'Settings -> Quick Setup' screen the selection at the bottom of the screen defaults to 'Standalone'. BUT the screen is showing the actual settings that have been made.[/quotePost]

This is probably the most egregious, lowest hanging UI/UX "bug" in the entire system. Used to catch me out all the time, now it just wastes my time, every time, as I have to check, double check and hope.

@Bill, - now able to reply to #117781 since the forum is back on.

My needs don’t currently include assigning parts from a performance separately. Perhaps I will discover such uses in the future. But I’ve only needed to use a Performance as one instrument, (hands-on playing), and recording it to one stereo channel is sufficient for now. This of course leaves all the other 8 USB channels free. I did however go ahead and assign individual parts to different USB channels to test what you asked about. I had no idea how it was going to work but, I must say this was intuitive enough.

So, I created a performance made of 8 parts. That entire performance was automatically assigned to Main L&R by the MODX. In my DAW I have the Stereo Main assigned to USB Main L&R by default. So I only heard the performance (all 8 parts simultaneously) sounding in the Stereo Main. I’ve created 8 additional mono inputs in my DAW, and named them Input 1 -8, but nothing is coming through any of them as the remaining 8 USB outputs from the MODX are not used. The performance is sent only to Main L&R. Thus, I am free to use USB 3 for the MIC.

Now, in order to simplify a little, I made another performance made up of only 3 single-part instruments: an Acoustic Piano DA, Orch Marimba, and Orch Glockenspiel. So I have a performance with only 3 parts. They too were automatically assigned to Main L&R in the MODX but I went and changed that.
Performance > Edit > General > Common >Part 1 > in the Part Output box I chose USB 1. Then I did the same for parts 2 & 3: - Common > Part 2 > Part Output > USB 2. Common > Part 3 > Part Output > USB3.
Then each part was assigned only to its own input in the DAW, namely, Part 1 (Piano) went to Input 1, Part 2 (Marimba) to Input 2, and Part 3 (Glockenspiel) to Input 3. You can see in the screenshots attached how only inputs 1-3 are active while nothing is coming through in the Stereo Main, and then in the track, if I select Input 1 I only hear the Piano, If I select Input 2 I only hear the marimba, etc.

I am sure it would work the same way if I made an 8 Part performance and assign it the same way to all 8 USB outputs. So I can use the 10 outputs however I want: I can put a performance on the Main L&R and have 8 outputs left, and use up only one for mic as is my current use, or I can assign each part to an output and have either 5 Stereo outputs, or 1 stereo (Main) and 8 mono outputs, or 3 stereo and 4 mono, etc.
My MODX assigns a performance to Main L&R by default and so, yes, the remaining 8 USBs were free.
I hope I understood your question correctly and answered it.
My most frequent gripe with the MODX, so far, seems to be the interface disconnecting, for lack of a better word. 1st symptom is when I start my DAW, if the MODx is already connected it will keep freezing up (the DAW) until I unplug/plug the USB cord. Then it works, though sometimes I have to do that a couple of times to work. Another symptom is when I have it on for a long time (a few hours) it again freezes, (the hourglass comes up intermittently). So that’s when I realize that Steinberg stops connecting or being recognized or something. I shut off the DAW and MODX and start over. Don’t know if others have the same problem. Perhaps I’ll ask that in another thread but I just thought I’d mention it.

Glad I could do it. Thanks to everyone for all the ideas and help