R3930 NVMe RAID1?

I'd like to set a dual (RAID-protected) boot drive using the 2 NVMe slots on the Precision R3930. I can't find anywhere how to do it… though it's hard to find something that doesn't exist, so asking here to confirm.

Even with enabling the legacy boot ROM (which I'm not sure is less-preferred for modern Windows), looks like Intel RSTe only supports SATA RAID?

So, no straightforward way to do it? (Aside from trying out a 3rd party, non-Dell-sanctioned PCIe RAID card?)