I have both of these devices and both have HDR on at all times. Unless I'm missing something, theres no way for HDR to be turned off or better yet, just a simple setting for it to detect when standard content or HDR is being displayed so it can adjust accordingly.
Because HDR is on at all times and most content I watch (including the damn menu) is standard, everything is completely washed out and looks terrible. I have no clue how these devices are being used in homes when this is the case, unless the average person just can't tell.
I don't understand why some devices have the option while others don't, for example, on the Formuler GTV there is an "HDR Policy" option that was introduced on Android 10 where you can turn that thing OFF, it's usually set on "Adaptive HDR".