[CentOS] [OT] how to give ssh options to rdist

Hello,
I'm trying to configure rdist over ssh so that it connects at target side
as a particular user.

I'm using CentOS 7.3 on both ends (I also tested with Fedora 25 with the
same behavor)

So I create at source side the file ~/.ssh/config under mysourceuser home

Host targetsrv.localdomain.local
     HostName targetsrv.localdomain.local
     User mytargetuser

Then, connected as mysourceuser user on local server

$ ssh targetsrv.localdomain.local
mytargetuser at targetsrv.localdomain.local's password:

So far so good as expected.

But if I create a small distfile to distribute a file on
targetsrv.localdomain.local and execute rdist on it, I receive the prompt
of mysourceuser password, not mytargetuser one....

$ rdist -P /usr/bin/ssh -f ./distfile distrotest
mysourceuser at targetsrv.localdomain.local's password:

It seems the config file is not honored. I tried different combinations but
none worked
eg creating a wrapper script that runs ssh -F config_file "$@"

I can workaround the problem using inside the distfile
"mytargetuser at targetsrv.localdomain.local" instead of
"targetsrv.localdomain.local" , this way it works.
But I would like to avoid it if possible as I have a distfile with many
entries and variables as destination hosts target.

Any help appreciated

Thanks,
Gianluca