Pixelpoet, thanks for that very excellent idea. I immediately tried it and find the combination of (Group 1) regular vibr. + (Group 2) progressive vibr. is indeed very lovely - but yes: it has me waiting a little too impatiently for that most beautiful espressivo vibrato to kick in.
Then I had an idea for ameliorating my impatience:–
I've just added a "Prog. vib" slot to the "XF vibrato" dimension column of Group 1, and then in the next dimension column I attached the relevant "Vib-progr" patch for each of the Group 1 players.
Now I can have both Groups in unisono start playing a note with regular vibrato until the (already triggered and silently running) delayed vibrato in Group 1 is established, then X-fade to my new "Progr. vib" slot in the Group 1 Sy Player.
I'll also add the same edit for Group 2, so I have the option of X-fading from regular vib to espressivo vib in both Groups as soon as the time is right.
Paolo, I add my request to yours. You and Pixelpoet have rightly pointed out that the Vib-prog patch is beautifully espressivo when its vibrato is established; so, as you suggest, surely it's possible to cut the front end off those Vib-progr samples to provide us with new Molto Vibrato patches.
(Lol, now I'm having wicked silly ideas about making some protest placards, saying, for example, "PLEASE VSL, give us Molto Vibrato in Dimension Strings", then a gang of us march up and down Engelshofengasse, waving the placards and chanting "What do we want?" etc. Lololol.)