Nope. Nope. Nope.
I know couples that do this. And they get in so many little fights about... everything related to this. Not cute fights either, where they end up laughing. Serious "we're breaking up and getting a divorce" fights.
Maybe I'm too old for this sort of thing. It sounds manipulative. I mean, if my partner were to ask to do this, and I said "no," wouldn't that open the door to some wildly speculative series of questions? And then we would know our locations...and what happens if it turns off? Or one of us forgets our phone? More fights over nothing. Or worse: Remember Courtney Clenney? One of the fights that lead to a murder was about location sharing.