Prefer IPv6 connections, and/or failover between protocols between nodes; also, chained gateways

[unquietwiki]

Maybe this is a WireGuard limitation, but right now nodes are pretty much dual-stack, with an apparent IPv4 preference. If there is a failure to connect on IPv4, it does not appear to failover to an otherwise-working IPv6 connection. Such a feature could also integrate a user-choice preference, per node, that would allow for traffic shaping of some form based on protocol access.

A second idea, that would pair nicely with the above, would be "chained gateways": be able to explicitly define peering between gateways, based on their available protocols. v4-only nodes could peer with dual-stack nodes, that peer with v6-only/preferred nodes. This arrangement/configuration could be determined by the sysadmin, rather than automatically.