What is your goal here? There is no difference between ::1 and 127.0.0.1 - both are the exact same local host. If you concerned about getting IPv6 name resolution - AAAA queries can be answered by an IPV4 reachable DNS server, too.
Not possible when unbound is listening on ::1 and 127.0.0.1. The topic, you linked to, shows I'm using addresses 127.10.10.2 and fdaa:bbcc:ddee:2::5552 to achieve this.
As others have noted, you can do this by eliminating the IPv6 Custom3 IP. Both of the loopback addresses you have specified lead to the exact same place. You only need the IPv4 IP. The functionality will be unchanged and you will see in a single pie slice of the chart all the DNS queries answered by unbound.