Disable ALL User Interface Sound Effects macOS Big Sur 11.5.2

I've filed a feedback report to Apple concerning this, but is there a something I can do from the command line to turn off all user interface sound effects that guarantees no sound effects ever play?

I own an entertainment business and I bluetooth my MacBook Air M1 to a sound system and play music. There are still sound effects that occur randomly and inconsistently with the bluetooth system. For example I have a bluetooth 4.0 handheld barcode scanner that is paired to my MacBook Air M! that scans barcodes for a game my patrons are playing. Sometimes when I turn on the scanner no sound effect occurs, but sometimes there is a very loud pop sound effect that is played when the scanner connects. It is quite loud and extremely annoying to me and my patrons.

I can produce this problem consistently using the Notes app, as an example. If I deselect "Play user interface sound effects" in Sound preferences and then open the Notes app and press CMD+S I hear the same loud pop sound effect. This should not happen if I have turned off the user interface sound effects, right? I understand the CMD+S is an error in Notes since there is not a "Save" command, but if I have turned off all user interface sound effects it seems to me I should not hear this sound effect. I can also repeat this same behavior on my Intel based iMac (2015) running the same os, so it seems to be an os bug.

I followed the instructions provided in another post here about rebooting, turning the setting on and off, and even trying safe-mode boot. None of these resolves the issue for me.

Like I asked above, is something I could do from the command line in terminal to permanently turn off all sound effects, regardless of whether it is an error, or anything else? I don't want any sound effects to run on my MacBook Air.