SFTP kioslave and ~/.ssh/config

[Alvin]

The situation:

I have a server 'leto' and a server 'ghanima' in the same network. SSH port 
50022 is forwarded to port 22 on leto.

In order to reach ghanima, I have the following entries in ~/.ssh/config

	Host ghanima.local.alvin.be ghanima
	  User          alvin
	  HostName      ghanima.local.alvin.be
	  ProxyCommand  ssh leto nc %h %p 2> /dev/null

	Host leto.local.alvin.be leto
	  HostKeyAlias  leto
	  HostName      <my-currently-hidden-ip-address>
	  port 50022

This is working fine from a terminal. "$ ssh ghanima" will immediately give me 
a prompt on ghanima if I log in from an external location.

This also works with fish://ghanima in Dolphin
This does NOT work with sftp://ghanima in Dolphin.
The error is: "Could not connect to host Failed to resolve hostname 
ghanima.local.alvin.be (Name or service not known)."

Since SFTP is the preferred choice, and also automatically used when choosing 
'ssh' in remoteview:/ I'd like SFTP to work. ("$ sftp ghanima" in a terminal 
does.)

Should I report this as a bug?