What is the use case of per client blocking?

Blocking Facebook stuff on every device except my wife’s phone.

Why not just tell your DHCP server to give her the regular DNS servers? Is this situation where she wants ad blocking but still wants to use FB?

Not OP, but in my case, most of my VLANs can’t perform DNS requests to WAN. Only the pi.hole server is able to do that (and other devices in the DMZ).

Reasoning: appliances like Chromecast/Apple TV/whatever will often ignore DHCP DNS settings if it doesn’t resolve, and they’ll reach out to 8.8.8.8/8.8.4.4 directly.

Yeah, ad blocking in general is what makes the web tolerable.

I have several users and multiple devices in our household. FB is not allowed anywhere near my PC, but wife has to currently switch between piholed and not piholed wifi. It just allows for a much better control. Heavens know not everyone is like me.

Families and shared accommodations.