Hi Paul,
Good question about those portamentos, they are not planned in the near future.
My suggestion is to mix other libraries in for that purpose, like the Dimension Strings (portamentos are already available in SYNCHRON-ized Special Edition Volume 5, for eample). Adding just one desk to each section and featuring them prominently in the mix will get you great results.
Sllurred Legato Xfade vibrato is probably something that can be built - I will look into that.
Best,
Paul
Paul Kopf Product Manager VSL