Sakai is currently using an old version of opencsv 2.3
It looks like 4.1 was released in November 2017. It sounds like there's a lot of good changes here but updating to it might take some work as backward compatibility is broken in 4.x (and possibly 3.x)
Opencsv us used across the board in lessons, signup, assignment, profile, gradebook, site-manage- admin-tools and jobscheduler. From what I can tell they all use this shared version and the license for the new version is still fine.