@SchwarzeLocke @mptcp good point. I don't know how it works with Nautilus, if "mptcpize" can help directly, or maybe by modifying the SSH config, adding something like "ProxyCommand mptcpize run ssh %h:%p" (I didn't try)
If you find how to do that, I can add this on the mptcp.dev website
@matttbe @mptcp Coincidentally I've installed mptcpize this weekend to look into this. I am also thinking that ProxyCommand is worth looking at, but I haven't gotten that far as I still was not able to use MPTCP with "mptcpize enable". I guess I'll wait for the systemd update to reach Debian backports and then try the new SocketProtocol.