I edited my custom Playback Template ("VSL Full Orchestra), and replaced the older manual playback template (“VSL Vni I Dim 16ch”) with a new one (“VSL Strings Winds (PT)”).
The, I clicked on the Apply button to let the playback template be applied to the instruments.
It seems there is no way to let the instruments take the new template. I also deleted all the VST Instruments, and then reapplied the Playback Template. But the old manual playback templates were applied again, even if they are no longer in the Playback Template.
PS: I hope you can find a clearer terminology. What is selected with Play > Playback Template, and what appears in the Entry list, is not the same type of object, the latter being a subset of the former. Then, it seems that the Version History, the Playback Template, and the Endpoint Settup are using different names for the same object.