Get him a laptop early. Teach him how to make things. Separate “creative time” from “consumption time”. Get a router that gives you good controls for total time and time schedule. The TP-Link Deco series is what I use and it does the job. Avoid a real smartphone for as long as possible. 9th grade would be ideal. Give other ways to communicate - smart watcj, dumb phone, Discord on laptop. This is about manners, litera…
Learning apps or anything that requires imagination have no or very few screen time limits.
100% consumption like Netflix, D+ etc have hard daily limits and the kids can get more by doing something that doesn't require a screen.
Now we're at a level where the media viewing very rarely occupies them a 100%, in most cases there's an iPad or a computer playing a kids show for the 42nd time just as a background noise while they're doing crafts or something else.