The gigaversion of the chamber strings does already have the Release-Control mappings (+RC). I don't know at the moment how this feature is managed in the Kontakt version.
Personally I would not programm a phrase exclusively using portamento articulations. Switching between normal legato and portamento should give authentic sounding results, because that's the way real players would perform it.
Another realistic solution could be to stack solo violin and chambers, some portamentos performed by solo and chambers together, and some portamenti only by the soloviolin (chambers normal legato), and maybe vice versa,
This offers a higher level of randomness and I'm sure it would sound pretty realistic. But Again, I wouldn't add portamenti to all notes.
best
Herb
Personally I would not programm a phrase exclusively using portamento articulations. Switching between normal legato and portamento should give authentic sounding results, because that's the way real players would perform it.
Another realistic solution could be to stack solo violin and chambers, some portamentos performed by solo and chambers together, and some portamenti only by the soloviolin (chambers normal legato), and maybe vice versa,
This offers a higher level of randomness and I'm sure it would sound pretty realistic. But Again, I wouldn't add portamenti to all notes.
best
Herb