The 50% number was made up anyway, it's likely higher than that. GPS especially is pretty accurate, and these tracking systems probably use it when available.

For a single stolen phone, probably not. Though you can still go to their house and then call the phone right as they answer the door. If you hear ringing then that's probable cause.

Either a location is enough for the police to search your place or it is not. Don't pull the kidnapped big eyed little girl card, please.

If crime1 w/ probable cause means you enter the building and crime2 w/ probable cause means you enter the building then there's no reason to bring up tiny girls or puppies.

But obviously there is a difference between trivial crimes and kidnappings. Inconveniencing a few people to save a life is acceptable. The expected utility is positive. It likely is not for more trivial crimes.