Now that Beta 6.0 is moved to development, I found time to try out with Unbound.
Followed the setup instructions found on https://docs.pi-hole.net/guides/dns/unbound/?h=unbound.
So far Unbound is running fine on both Pi4s.
Just got a question
In the Unbound log this message is found Sep 22 10:38:54 unbound[4924:0] warning: subnetcache: prefetch is set but not working for data originating from the subnet module cache.
Is this normal and can be forgotten?
Thanks again for all your effort and great feedbacks to questions/issues!
Apologise if above question has been raise before.