Authentication not passed from coordinator to datanodes (trust required)

I'm opening a ticket because I can't seem to post to the list which is where I think this should go. First of all, good work, I really like Postgres-XL and I hope that it has a future. I'd love to contribute in any way possible. I've attached a TDC which allows Tableau to connect to Postgres-XL using the psqlodbc driver (Tableau 9.0, psqlodbc 9.3.003).

I've created a single server, single coordinator, 8 datanode (master) instance of Postgres-XL. Initial testing is fine but I'm trying to wrap my head around authentication. I have connected the coordinator to ldap for a particular group, authentication to the coordinator for members of this group works fine and if I use trust for the same group for connections from the host for all of the datanodes then it works fine, however, this allows a local user to connect to any authorised database if they are on the host, something that is not idea. I've tried using ldap authentication in the datanodes as well but then I get the infamous pooled connections error (can't connect to). The configuration below is currently working but is not ideal:

Coordinator pg_hba.conf entry:

host all +tport_users all ldap ldapserver="myldapserver.mydomain" ldaptls=1 ldapprefix="uid=" ldapsuffix=",ou=people,ou=everyone,dc=ic,dc=ac,dc=uk"

Datanode pg_hba.conf entry:

host all +tport_users my.ip/32 trust

Ultimately I want 1 local super user authenticated by password for all nodes + roles with members authenticated by ldap for all nodes. If I do anything but trust in the datanode pg_hba.conf however the pooled connections error comes up.