Thank you for explaining that, it sounds very similar to Denon and Marantz's, but again that's not my question. My question if whether users who only have 5.1 speakers can take advantage of the feature to "disconnect the front left and front right channels. Again, I am asking only because as you said "The line to the amplifier is muted when you select Ext Front.", and to do so, one would have to select one of the three 7.2.X I listed and you repeated above and then the question is, can I then reconfigure the speaker to a 5.1 layout and still have FL/FR power amp channel remain disconnected. I wouldn't use the term muted because it isn't a mute function, though the circuitry used would almost certainly be the same.
To help clarify my question further, I can tell you for a Denon, as an example, I have to select one of those 7.2.X configuration to disconnect the FL and FR, but after that is done I can go back to the speaker menu to configure the layout to something else, even just 2.1 and the FL and FR power amp channels would remain disconnected. Can we do the same/similar to the Yamaha, that's the question and I hope it is clear this time.
Thanks again for your patience.