in this case, I believe the best solution would be to use secure gateways. That way you could set up the secure gateway(s) and then either inherit them to all the following connections or select which ones (secure gateways) to use for which connections. That way you could save your secure gateway(s) and also all of your VNC connections too. For more information on secure gateways, please refer to the following link: https://www.royalapps.com/blog/new-feature-secure-gateway-ssh-tunnels
I hope this helps!
Thank you, I've tried the secure gateway, but I have authentication via the ssh-agent not a file. The key is held in a variable in the ssh-agent in a Unix Socket. Is there a way to use the secure gateway in this manner?