How to create exFAT or NTFS RAID 1
I created a RAID set using two USB sticks with Disk Utility in macOS Sierra 10.12.6. While I was only presented with Mac OS Extended options during the setup, once the RAID set was created I could erase it and choose another format.



After formatting the volume as ExFAT, I was able to store data on the RAID set.

However, I can't say what standard of RAID is used creating these sets. If you intend to connect the RAID set to another OS other than macOS, your millage may vary.