I would like use monitor, but is not possible.
If you are on Windows search for "Mouse without borders". With it I run rigs off of one monitor.......my main PC monitor. Of course another option is to SSH into each rig from a PC/laptop using something like "putty".
In my case Monitor means remote monitoring and not display. For display information on monitor I don't need newer client
I'm able working with mouse and keyboard. Windows or Linux doesn't matter for me

ssh, tunneling or VPN, NAT, masquerade what do you want
