Refresh my memory: If I have a set of two HDDs in a Raid 0 configuration in a 5.1 Mac Pro on Big Sur, can I move the set to a new 7.1 and expect Big Sur on the new Mac Pro to recognise the structure and configuration of the Raid set?
You can just make a quick experiment.
1) Format a USB thumb drive on the 5,1
2) split that thumb drive into two partitions (e.g. for a 16GB thumb drive, make that 8+8)
3) RAID that two partitions inside disk utility in RAID 0
4) copy some files onto it
5) move that thumb drive to the 7,1 and see if the 7,1 can read the files
If you want a more accurate test, you can run this test with two thumb drives to simulate two hard drives.
If that works, it means you should able to transfer the RAID 0 array to the 7,1. Of course, no guarantee.