I'm not sure what else DNSFilter is adding, but my query log is logging IPv6 client addresses. There is some functionality of IPv6 with the relay servers, but hopefully they are developing ability to put certain IPv6 subnets into specific profiles (i.e., 2000:100:1500:1::1/64 in one profile, 2000:100:1500:2::1/64 in another). This is offered for IPv4 subnets via the LAN Subnet section of the relay configuration.