Thank you for playing ball with me, @benwiggy. From the way you express your saving of “..the Endpoint as ‘Trumpets’” I got the idea that somehow there needs to be another way of saving endpoints. A way that includes multiple VSTs. I did a new experiment:
I have been using the Big “Save Endpoint Configuration” Button inside the endpoint configuration:
This button only saves the current single instance endpoint, resulting in a playback template which doesn’t alternate between different patches for the same score instrument (e.g. “Violin” or “Horn”).
Now I tried instead the button for saving endpoints (with an arrow pointing to a kind of drawer) at the bottom of the VST list:
It never occurred to me that this button didn’t work like the two plus buttons beside it, which operate on a single / the selected VST, but indeed on the whole set of VSTs, thus including multiple instances of independent VST instances.
The endpoint thus created and included in a playback template results in the desired alternating behavior. At least I have been able to reinstatiate three flutes with the different SINE instances, and when I add a fourth flute it gets the playback of instrument of Flute 1.
I think this difference should somehow be more obvious. My immediate suggestion would be a button with three dots, opening a menu for operations on all VSTs, like the multi-instance endpoint considered here (and e.g. “purge deactivated”, but that is another toast), but surely some Steinberg UX person will have an idea and policy considerations to honour.
Another thing is documentation. Even if I have been looking around, I have not been able to find this information. Now that I know what to look for, the functionality of the buttons is actually described in the Steinberg Dorico documentation “Custom Endpoint Configuration”, except that saving “a custom endpoint configuration that includes all VST instrument or MIDI instrument plug-in instances” is required for the alternating instrument playback functionality is not made explicit.
Well, I hope I have not drowned my own intention of making this clear by writing too much. I often do, I am afraid. I hope this insight contributes a little to this forum, where I have found much help myself.