Hey Jay
So I ended up with the RX-A3070 and am using the RX-Vx73 Series version of the plugin. The plug didn't "auto find" the receiver, but all I did was manually enter the IP address and the rest went as planned.
From what I can tell, all of the prescribed action groups work just fine, including the "Play Net Radio Station". While I didn't go thru every single input, the ones I have connected to the receiver work perfectly, but when I select an AV input that has nothing connected, the following loops in the Event Log until I switch it to an input that does have something connected.
Action Group Set Input
Error cannot update device state for key input to value AV7 (invalid enumeration value)
Error cannot update device state for key input to value AV7 (invalid enumeration value)
Error cannot update device state for key input to value AV7 (invalid enumeration value)
Error cannot update device state for key input to value AV7 (invalid enumeration value)
Again, thanks for everyone's help on this. Having read all the threads here, I was a bit concerned that Yamaha might have different IP protocols for different receivers... and they may... but the RX-A3070 works just fine, and I'd even go out on a limb and based on my limited experiment, say the RX-A1070 does as well.
Its a beautiful day in Indigodomo Land! Thanks again for all the great work of everyone involved.