Jails on DragonFly can now route to loopback addresses (i.e. 127.0.0.1). Because of this, they can work like shared IPs and the jail can connect to the host.
I think this means that you no longer have to bind jail services to specific IPs as you did previously. Don’t quote me on that; I’ve run few jails in my life.
Update: I should have linked this too: the sysctl jail.defaults.allow_listen_override that makes it easier in the host system too.