Except we’re not talking about the finer points of HDMI and CEC like volume and power control or universal remote capabilities. Or with the Ultra specifically, how the TV behaves when the Ultra is set to different inputs or outputs.
The case I’m talking about is pretty fundamental. One of you wants the TV to always see the ARC connection, even in standby, and one of you (plus me) wants the TV to see it only when the Ultra is fully powered on. That’s just a matter of completely disabling the HDMI port when the unit is on standby, or not, and letting that behavior be set in the app. If the Ultra’s HDMI completely shuts down it doesn’t matter what the peculiarities of the TV model are. It simply does not see the ARC endpoint, just like if you had a loose HDMI cable plugged into the TV. Nothing happens.