Should turn volume on screen display off. In the video section, actually turn all of the "on screen display" off, that prevents all the ugly shit from the receiver from overlaying on the the screen.
Should turn off AirPlay, because we'll never want to Airplay to the receiver. We only play Spotify through Spotify Connect. This prevents us from making a mistake when trying to play Music.
Should hide all sources except the ones in use (likely just Shield and TV Audio).
Rename "SHIELD" to "Shield"
Rename "TV Audio" to "eARC"
Change 4k Signal Format to "Enhanced", this will allow for Dolby Vision. You'll notice with this not set to Dolby Vision, the NVIDIA shield doesn't let you output 4k 60fps Dolby Vision as a resolution option, it only allows for 1080p 60fps, Dolby Vision and HDR10: https://www.reddit.com/r/nvidiashield/comments/evftbj/shield_tv_2019_and_hdrdv/. Note that there is no difference between 60Hz and 59.940 Hz: https://www.reddit.com/r/pcmasterrace/comments/71x8x3/what_is_the_difference_between_599_hz_and_60hz_on/.
Turn Eco mode's on screen display to off.
There may be some advanced settings that could be changed, but a provincial look got all of the main things we'd want to change.
Still not sure how it know whether to do 5.1 vs 3.1 etc based on what's playing? Seems like that's metadata that's sent.
Here's the manual to fully understand all the settings: https://manuals.denon.com/avrs750h/na/en/download.php?filename=/AVRS750H/NA/EN/pdf/AVRS750H_NA_EN.pdf