Celestial Navigation is also doable even in daylight nowadays, e.g. https://sodern.com/en/ranges/astradia

Will that come as an option for my RAV4 or F-150? How about my Cessna?

Will it help keep my NTP/PTP masters sync'd?

It's been doable since the 1940's.

https://patents.google.com/patent/US2981843A/en