@Phiqu. Although this was an answer that I didn't expect or look for, it worked great! And it was very easy copy/paste from your answer, thank you very much! Problem solved.
I needed only install-part of it because I remembered that I'd just recently and first time needed software *(alsa-scarlett-gui), which was available only flatpak, so I had already done installing flatpak + added flathub repository.
*https://github.com/geoffreybennett/alsa-scarlett-gui
@ReillyBrogan Thanks for confirming Phiqu's advise, it was indeed quite simple task although leaves me, again, wondering why is this seemingly simple task, relatively complicated. But, perhaps new thread for that.
