I like the idea. We tried with licence free walkie talkies, but it did not catch on. What it worked is the xplora watches. Only approved contacts and we can also contact our kids and check GPS position . They are a bit buggy sometimes but mostly fine

Yeah I've seen some parents use this to great success. Seems to also allow them more freedom to allow kids to explore a bit more on their own. Like it's the 90's.