GPS Tracker for Special Needs

I have a 9 year old with Down syndrome. Unfortunately, he has eloped a few times, leaving us shattered and not knowing which direction to look for him . We've tried multiple GPS trackers, but they just take too long to upload his location and haven not been effective. Question: Could an Apple Watch Series 5 work as a GPS tracker? I would use the cellular plan so he would have coverage without a phone attached. I'm assuming I could use "Find my Phone" to locate him if he is lost. Thoughts? Biggest worry is him losing it (or it getting stolen), but we'd try to secure it daily with some type of wrist band "lock" so he couldn't pull it off. Would love to know if you think Find My Phone would be a quick locator if he elopes again? Thank you!