SCP Remote-To-Remote?

[Peter Lambrechtsen]

I have seen discussion in 2005 around SCP Remote to Remote support.
And wondering if there was any plans to add this into OpenSSH?

Specifically I am talking about this e-mail:
https://lists.mindrot.org/pipermail/openssh-unix-dev/2005-May/022953.html

The situation I find myself in is I can SSH into two of our servers
sitting in two different DMZs from out Bastion host, however the two
servers are unable to contact each other, nor are they able to SSH
back to the Bastion host.  Of course since this is a BH, it has no
locally writable space so I am unable to copy them locally.

The "tar" solution in the above e-mail works, albeit a little ugly.
Ideally I would like to be able to:

scp -MITM user at host:/directory/files user at host2:/destinationdir

And the traffic be routed via the local server, instead of trying to
connect directly (as there are no routes between the two due to
security and firewall restrictions).

Ideas as to if this may be supported in SCP?

Thanks

Peter