Is it safe to expose the Amazfit T-Rex Ultra 2 to extremely low air pressure?

No, subjecting the watch's battery to extremely low air pressure may result in an explosion or the leakage of flammable liquids and gases. You should also avoid crushing, cutting, or exposing the battery to high heat sources like ovens or heaters. The built-in battery is non-removable and should only be handled by authorized service centers.