No to an Air Tag if he does not want it.
If hIs phone is lost/stolen he asks in a café, shop, even Police Station, if he can phone you or another responsible adult. Surely he knows your phone number to call in an emergency?
Adolescence is about developing independence and this level of constant monitoring may undermine his ability to make decisions, manage risks, and learn from mistakes.
This AirTag obsession might delay his development of self-reliance/risk assessment if he grows used to the idea that you’ll always be able to “rescue” him.
surely you want a strong minded, independent, son? Isn’t that the end goal in parenting?
I had to learn, ‘street smarts’, I had to trust my gut, and make choices. I did make some mistakes, but I learned so much from making them. I bet you did too?
Let him know you support him, that he can always call in an emergency, that you will come -no questions asked, if he needs you. Say again, if he ever wants the Air Tag, you will supply it
Then let him live his life, mistakes and all!