For the TSA, here is the reference I used to determine if it was ok or not.
https://www.faa.gov/hazmat/packsafe/..._batteries.pdf I was not able to find a more updated version so I am "assuming" that is up to date. Since the AirTag device uses a button style battery, appears ok on that front.
I have actually had very good experience with them in my luggage. During a recent lost luggage situation, I was able to watch it fly around the US. Also watched it sit in Phoenix and not move for 3 days......... It is pretty cool but you have to love Apple piggy backing peoples phone and not event knowing it.