Current system has several drawbacks :
- vnc enable sometimes hangs for hours and users are unable to do anything
- noVNC doesn't have a full-screen option, developer doesn't have time to implement scaling
- requires browser
I suggest you allow users to connect directly to the VNC nodes using any VNC client.
I understand security concerns, you can have the "VNC" enable function open a random port, and keep it open for new connections only 30 seconds for example.