Alienmoon,
You will loose the array if you flash. Based on feedback from others, all have lost their m.2 arrays after a flash. As ElectroStingz pointed out, the ability to recover varies and is based on several factors. I myself have recovered using Legacy option ROM and SSDs and/or spinners, but NVMe's has thus far proven difficult since the RAID Option ROM has not been included in the UEFI portion of BIOS.
About BIOS revisions and betas. Ones ending with a letter. IIRC @BIOS only displays "final releases" not betas, but the option to display betas might exist (checkbox) depending on the version.
Follow ElectroStingz suggestions. Make a full Disk Image Back Up of your array. Either Acronis or Macrium works great for this. Validate the image (just takes a few extra minutes). Try removing the drives and flashing using qFlash. After flashing, reinstall the drives (same slots) and start the system. Enter BIOS, Enable RAID and mark the m.2 as members. See if it boots. I have to be honest, the probability of success since this is RAID 0 is 1%.
Now restore your previously created image to the array and post your results.