My understanding is that it is on by default if you use it. If you haven’t enabled Find My $device it is _not_ turned on by default.
Of course that isn’t much of a distinction since the vast majority of iPhone users will
have Find My Phone turned on and I believe are encouraged to turn Find My Phone on during device setup.
I stand corrected. Just turned off “Find My iPad” and the switch for “Find My network” disappears. So I guess it’s “opt-out of this if you’ve opted in to that”? Regardless you are right, thanks.
This is my understanding too, it isn't immediately clear so I understand the confusion but if you do not onboard your device into the network on setup, you won't be pinging other devices (like AirTags) via ULB Bluetooth
Of course that isn’t much of a distinction since the vast majority of iPhone users will have Find My Phone turned on and I believe are encouraged to turn Find My Phone on during device setup.