Yes, in Alt-Az mode, the Seestar does track the object during the exposure itself—not just between exposures. This means that during a 10, 20, or 30 second exposure, the mount continuously moves to follow the object across the sky, minimizing star trailing.
However, because it’s an Alt-Az mount, it cannot compensate for field rotation during long exposures, which can become noticeable at 20 or 30 seconds depending on the target’s position in the sky. That’s why longer exposures are typically stacked rather than used individually.