The Spatialize Stereo toggle only affects stereo tracks. All compatible Spatial Audio tracks will automatically play to both users without any configuration after pairing both sets of headphones.

Generic HRTFs are also used to spatialize stereo content or improve head-tracked spatial audio. If your music app, wireless headphones, or wireless earbuds have a spatial sound mode, it can be ...

The new Immersive Audio tech will impact battery life, and Bose is upfront about that. The company says that with that spatial sound enabled, you can expect two hours less of playing time per charge.