For Home Theater setups (Arc, Playbar, etc.) either standalone or as a full 5.1 System (Sub + Surrounds) I think users would appreciate the ability to have multiple presets to automatically switch based on source (or, although this is less useful, at a minimum manually toggle via a single button switch in the settings)
For example for HDMI Input (TV) content I much prefer Trueplay tuning turned on as it improves sonic performance incl. speech which becomes clearer and I get better Atmos performance. However, I find Trueplay does not sound good with Streaming Audio from sources such as Spotify, Apple Music, etc. as I suffer from the metallic/harsh treble and loss of mids.
I would suggest a feature so that a user can save custom presets (incl. Trueplay + EQ Setings + Sub + Surrounds settings). If the Arc can switch to that once it detects an HDMI input from the TV but then have the ability to switch to a different preferred profile automatically when it detects music that would be ideal.
These change as I keep adjusting but right now for TV I have Trueplay ON, Sub -2, Treble -1
For Music I prefer to have Trueplay OFF (tinny/harsh sound with overly boomy bass with it On), Sub +2, Surrounds set to Full.
This would save a lot of individual settings that I manually toggle constantly depending on what I am using the system for.