Bob, thanks. You're spot-on as usual!!
That's what Anthem wrote back as well and the three button macro combo does indeed work like a charm to access each of the virtual input sources. I just did a test and it passed with flying colors.
I'm assuming that the macros are identical for the D2v. I'm trying to work with the Roomie folks to update the AVM50v file to take advantage of the additional virtual inputs so that it's there out of the box.
I'm using them, so I want to be able to share the work I'm going to do with others.