When I need to make a change to one of the instances I work on one container and then copy it and paste container contents on the other instances. The externals being internal to the container and the container being externalized.
Hopefully I am missing something Can someone tell me how this can now be done?
Attached is a simple Ventuz3 scene with externalised containers to show what I mean.
This is quite fundamental if I can't do it in Ventuz4

Any help would be great, thanks!