I noticed my Note 8 (Verizon) just updated to Android 9. I also noticed this:
Settings > Developer options >
Force GNSS measurements: Track all GNSS constellations and frequencies with no duty cycling
Can toggle OFF and ON (OFF by default).
What is this? Is this only for devices that are GNSS capable for better accuracy than typical GPS. i.e. meter accuracy vs. 3 meter accuracy?