Given that the OS in the CIC was designed for a hard drive, and there was a need to save flash ram space and the age of the CIC, trim support is not present.
But it isn't really needed anyway... see this.
https://www.crucial.com/articles/about-ssd/what-is-trim
I've been running mine forever a few years now without a single issue nor hiccup.
And it is nice to have the original drive as a backup.
Btw: if I remember correctly, the CIC will not work with larger drives, so your choice is important.