I’ve just set up my pihole and I’m considering the best way to configure it. Is it a good idea to set the default group to block (almost) all domains and then manually add trusted devices to another group with a “normal” block list? My use case is untrustworthy devices that I don’t want phoning home but which might change their IP address.
Pihole doesn’t block inbound traffic, it has nothing to do with it (as you mention in your later comment, DNS is about address lookups, not routing IP addresses).
PiHole is a DNS server, all it will do is resolve addresses for clients that use it.