ASad you've deleted the question because I'm interested in this too 
BI had some luck going into the bazzite desktop, right clicking on the audio in the task bar, and then disabling the ones I didn't want to use
AHey, I've been lucky yesterday to finally resolve my problem! So the problem was that on each Asus ROG Ally's restart, switch to desktop and back to console, or sometimes after sleep too, Bazzite has been switching default audio output device from the one I have no problems with (Family...) to the quiet one (ROG Ally). Turns out that there's no need to even try setting the Family... sound output device as a default, but instead, all I need is to push the Family... device's volume to the max, and that will increase the maximum value for the ROG Ally's volume as well. So now I'm using ROG Ally sound output device without problems.
