You can just load a 9400 xcf that has never seen the 9600 editor into the 9600 editor and the system page will be set. All the system widget names are the same.
You must first open the 9600 editor and then within the editor, open the desired 9400 xcf. I have been doing just that with slimPronto-94 for the past year
One note of observation, when either editor saves the file it marks it so that windows knows which editor to load if you double click the xcf. You can always load the xcf into the editor of your choice using the method described above.
I also do all my 9400 debugging (except for visual image approval and color rendition) on the 9600. This is because I can use the PC based Debug system instead of trying to stare all day at the very limited _PS_Debug_ panel of the 9400. TCPIP work is much easier when you have a scrolling window on the PC holding all System.Print data in 12 point type, well at least for my 68 year old eyes it is.
