

Pihole can set up “groups” for different blocklists. You specify client by IP or MAC address so it doesnt matter what the dhcp server is, so long as there’s a static IP or static MAC address. My pihole server doesn’t have dhcp set up and I’m able to do this fine
Though from personal experience this just becomes a game of cat and mouse, and if you have a motivated teenager then they will find a way to circumvent this. For example android can rotate MAC addresses, and IP addresses are trivial to spoof as well.
These are just off the top of my head. Best case scenario the blocking does work and the teen never tries to bypass it. They’ll still just move onto “wasting” time on something else. This is treating the symptom and not the root cause.