Well, as usual with MS the devil is in the details. My Realtek HD Audio software disappeared. The drive installed, but no settings tool was in the tray, so no room effects or equalizer anymore. I tried installing a newer version of the driver (late Oct versus Feb 21) than the one Win 11 defaulted to, but it just did an endless uninstall, reinstall loop, and never finished. I think the default Win 11 driver was interfering with the ASRock install package.
I ended up buying a $14.99 copy of Boom 3D since I'm using only headphones for gaming speakers these days (happy wife, happy life), and that gave me full control over the soundscape again. Their game equalizer setting, and high fidelity filter really brings the game alive.