The lack of fast legato can be an issue with the chamber strings.
For my own purposes, I have found two options worth trying. First, use a long detache for moderately fast notes - perhaps moderately "non-slow notes" would be a better description (it sounds more connected than one would naturally expect. But, so far, I have not written something for chamber strings that requires rapid 32nds or anything that fast.
Another option would be, in VI Pro 2, to create a faster legato patch, something that is very easy to do, by shortening the initial attack %, and decreasing the following portion of the note (leaving the latter potion of the note at 100%).