I have 4TB Little Big Disc (9000466) and I tried replacing 2TB Samsung HDDs with Samsung Evo 4TB - Lacie enclosure failed miserably. I only got 210/220 MB/s speeds (test by blackmagic) regardless of whether SSD was the only drive installed or if it was also accompanied with another drive (non-raid configuration).
Surprisingly, my ancient Seagate Backup Plus Portable Thunderbolt Adapter (
https://www.amazon.com/Seagate-Backup-Portable-Thunderbolt-Adapter/dp/B009HQCARY) has performed considerably better with 4TB Samsung EVO SSD, resulting in 325/375 MB/s (yes, it does work, despite numerous reports saying that this adapter can only handle SSD with no more than 256 GB).
My conclusion is - Lacie's claim that Little Big Disc has "Up to 10Gb/s Interface Transfer Rate" is a flat out lie. They produce non-future prof garbage only to get your money.
P.S. I used Lacie's enclosure for ~2 years with noisy useless fan removed. I noticed no difference in drives temperature (max t = 99 degF).