It looks like HomePod and HomePod mini will soon have support for spatial audio and lossless audio via Apple Music. The HomePod 15 beta 5 includes options that enable lossless and Dolby Atmos playback.
Not all beta users will see the toggles, according to 9to5Mac. If you're running the latest iOS 15 and HomePod betas, you can check whether they're active by accessing the home options menu in the Home app, tapping your profile, then Media and Apple Music.
Earlier this year, Apple said it would bring Apple Music lossless streaming to HomePod and HomePod mini through a software update, but it didn't provide a timeline. Now, it seems the speakers will be able to stream lossless music soon (unless the option's already life for you in the beta).
Apple is expected to roll out its latest operating systems broadly within the next couple of months. When it does, you'll be able to pair a second HomePod mini to Apple TV for stereo audio.