Seems I've solved my issues with HDMI Input. Successfully connected a Dune 4K Solo media streamer. Passing video (1080p) and audio via my 203 through my AVR and TV.
Of course, since I had my initial issues, I've added the Dune, upgraded my AVR and upgraded the FW on the 203. Any one of these may have resolved the issue although I also note the two devices I was originally trying were both PayTV devices that might not like the idea of being connected to anything other than a TV or AVR. The Foxtel IQ3 doesn't even like the AVR - won't pass audio over HDMI.
Undoubtedly on purpose. Harks back to the early days of HDMI where Monster Cable in particular liked to show a demo with an HDMI cable or a "analogue" cable that turned out to be a composite cable (lowest PQ cable possible).
In my visits I've noted that the Demo loops are usually provided by the manufacturer, I suspect for display on their screens. That would seem fair.
You do sometimes see a loop for "A" on "B's" screen of course.
I think you are asking retailers to produce their own? Not sure they feel the need to do that
All else being equal, 2.4 vs 2.7m is not major in terms of the bass. However, in terms of having a rear row riser, bulkhead, Atmos and a large screen, having that extra height offers a more tangible improvement.