I don't think this is a huge ask, but it would assist me (and I'm sure others) in how I operate my TV along with secondary audio sources across a mixer board which is hooked up to an amplifier (think more commercial operations before Samsung is left in the past in businesses). Since there's no Analogue Audio outputs, this is very limiting:
As a feature request, I believe it would be optimal to be able to "mute" the "optical audio", basically to stop all sound coming form the optical port. So muting the TV at the source, not having to mute the amplifier which will stop all audio with secondary sources attached.
I understand controlling the audio levels (up/down) over optical is not possible, however muting the optical audio is possible. This should be able to be accomplished with a Firmware change, minimal effort.
Utilizing an ARC will not assist with the multiplexing without manually turning the knobs on the mixer board which defeats the purpose of a remote, and most mixer boards once you set, you don't really change the control knobs, and are generally locked away and hidden.
It's 2020, and technolgy is changing. On a $2,000+ Television, this is a showstopper. Not everyone simply hooks their TV to a Soundbar or to an Amplifier directly, nonetheless ARC is not used in many commercial settings. Samsung is one of the few manufactures with the lack of this ability, so please implement this feature since there's no analogue audio out.