Practical answer

External GNSS can improve antenna placement and temporal detail. The phone may still record its own fused location; select the external source explicitly and verify timestamps, receiver status and exported fields.

What to verify before track use

Position
Delivered and recorded update rate, fix quality and timestamp basis
Motion
Which sensors are exposed, axes, rate and raw versus fused values
Files
CSV, VBO, GPX, FIT, video metadata or proprietary session
Reliability
Background recording, heat, power, storage and interruptions
Do not infer a fixed GPS rate.

No fixed motorsport logging rate is claimed unless the device and app documentation explicitly provide it.

Primary sources