Depending on the terrain the loss rate might not be high. Put a cell phone in the package. Location tracking, find the phone. If they're dropping into ares w

Depending on the terrain the loss rate might not be high. Put a cell phone in the package. Location tracking, find the phone. If they're dropping into ares with cell coverage and flat enough that they're likely reachable then you won't lose a lot. And if you're dropping into areas without coverage you put something like an inReach on the balloon, set to send out pings. And put an AirTag or the like in it because the balloon might land on the transmitter and block it. (I own an inReach, know it can send pings at 2 minute or 10 minute intervals, I've only used them to look up where I was once (the real reason I have it is the SOS button works pretty much anywhere and even if I couldn't push it S&R would look up the last ping) but the website was spot on to normal GPS accuracy. There are competitors but I do not know their capability.)