I have a Garmin InReach and it can send location periodically. While it is more effective to have it out and pointed at a satellite, it still works in my pocket, but may just take a little longer to send the messages. For a feature like Find My, many people won’t mind if the location being sent is a little stale, but with emergency SOS, you really want your message to go out ASAP, so it makes sense that you need to point at a satellite for SOS, but not for Find My tracking.