System started out as new HP Z4 G4 with 256GB NvMe M.2 SSD as boot drive, running from motherboard NvMe slot.

Used Macrium Reflect to successfully clone the single drive to a pair of 2.5" SSDs running off of Adaptec hardware card. No issues, booted first time, etc.

Removed 256Gb NvMe drive, replaced with pair of 1Tb NvMe M.2 drives, easily set to RAID1 using Intel RST and with Intel VROC hardware key - the key (allegedly) makes the array bootable, and the HP BIOS settings confirm this.

Again used Macrium to clone the Adaptec RAID1 install of Windows 11 to the NvMe M.2 RAID1 array, proceeds normally.
Unplugged Adaptec drives, rebooted. Windows sees nothing to boot from.

Also then tried using Macrium to boot to Windows PE, which fails due to a PnP driver issue. Unsure as to how to proceed at this point. Macrium is time-limited trial version.

TIA for your ideas!