I haven't purchased any air tags, but was considering doing so for each of my cars.
Another thought I had was to put them in my kids shoes, mostly the youngest one. not sure if I could do it without her feeling it though.
I was curious on how the anti stalking worked as well. I think my cars would be fine, as the only ones that would most likely be affected would be my wife and older children that drive, but if it was on my 6yo, not sure how that would work with her going to school and being around people with phones like her teacher.