Hi George,
I understand you desired workflow, I used to work like that during a short period where I was new to orchestral samples and had hands onto the EastWest Orchestra. As those were my first steps into virtual orchestration, most of the times 4-5 articulations seemed sufficient to me. When I moved to Vienna Instruments, I tried to implement this workflow and - just as you - had to learn, that this is not possible within VI.
But, I also learned, that the note-by note midi-channel is a unique Logic-feature. It is not possible to assign an individual channel per event in ProTools, and I do not know, if it is possible in Cubase or DP.
However, when I started out to really use the abundance of articulations of the larger libraries, I soon realized, that the limitation to 16 slots would not be acceptable for me either, so I changed my approach to using keyswiches, and I advise you to do so as well.
Anyway, your repeated insisting on noting that VI is not multitimbral is not helping. You are ignoring all the hints, that you are comparing the wrong products. You have to compare Play/Kontakt with Vienna Ensemble (and not with VI). You can load 16 VIs into one VE instance, and you load the desired articulation into each VI. Tho whole setup can be stored from the VE host (as viframe), so that all VIs including the loaded patches can be restored with one mouseclick - exactly as you would do using contact.