I had no idea the receiver couldn't do a 7.2.6 and 9.2.4 swap easily. I was under the impression when reading about the 15 assignable ports and that the terminals (9.x.6 in theory) were for swapping configurations based on not just format but also tracks of the format. Is the only 15 channel/13 active config for just Auro-3D FCH and VOG? and nothing else? Is this a firmware or hardware thing? Even if firmware I'm not sure I'll hold my breath. I'm a little disappointed because I've always preferred my Marantz AVR's to Denon's and I would have picked up the 8805 had I known. But maybe there's one option, the app.You do have the "6 heights" option with a 9ch base layer, but again the extra two heights will be Auro3D specific. For example you can do Front Height + Surround Height + Rear Height, or Front Height + Center Height / Top Surround + Rear Height.
A 7.2.6 setup does not use the terminals for FW's, so I could have those connected concurrently to the FW's. In theory it seems like I could use the app to switch configurations between 7.2.6 and 9.2.4, and that would restore all audyssey adjustments for each. I'd have to do this manually depending on the movie I'm watching but is there any reason this wouldn't work? Does switching configurations take long via the app? Any downsides of switching if actively using the AVR if I start a movie, check incoming codec/available channels then change configs if needed? ... And I don't imagine there's a way to have a home automation system send IP or serial commands to swap configs if stored on a USB drive?