Hello Bob,
As previously stated, it is a needed improvement.
My time is heavily consumed right now, so your patch will be gratefully received.
My only comment would be that once connected to the cluster, notifications are sent to all nodes anyway, not just the one specified in the notification address parameter. So practically, the only need for resolving multiple records is on start-up to find the first available node. Upon contact with that node, a list of the other nodes is returned, all of which are stored and included in subsequent notifications - this is fairly fault-tolerant, providing your network is well designed. It is not tolerant of network splits etc, where it could be possible to end up with two or more separated clusters or split-brain type situations. However, to overcome that, I think we're looking at a *major* redesign - far more than can be achieved with multiple notification addresses. We'd also likely need to consider quorum, voting a primary/master etc. to do it properly.
Otherwise, it is a welcome addition in my opinion.
Cheers,
Charles