Record Raw on 2 cards - greyed out - UMP G2

Hi, I have a brand new UMP 4.6K G2, with firmware 6.4 and two KomputerBay 3700x (recommended for highest speeds). But I can't select to record on two cards, and therefore limited to only 60-ish FPS (at 3-1 ratio), both cards work fine. I formatted both for Mac and Exfat but can't seem to be able to make it work. Any suggestions? This is my first time with the BMD's so I might be missing something fundamental here.

Thank you!

The feature of using two cards had been implemented for higher frame rate recordings in CDNG raw. This was possible, because CDNG raw is a series of single images written into a folder. So the camera could write frame 1 to card A and frame 2 to card B. Later you had to combine the folders into one on your computer.

With BRAW and its better compression capabilities there is on one hand no need for distributing the data flow onto two cards and on the other hand it isn't possible to split, because BRAW is a single file format (with a secondary sidecar file).