Backup of Cloud Home Duo by exchanging disks?

Hi guys,
after searching through the posts I did not find an appropriate answer (or it was unclear to me).
Anyway:
I would like to periodically backup my Home Duo by exchanging one disk in a round-robin manner.
Means:
2 Disks in Duo, 1 spare disk locked away.
Then put spare disk into Duo, have the RAID rebuild (so effectively I now would end up with 3 disks and the same data on it) and lock away 1 disk.
Then, repeat this procedure every X months.

Would that work? Any pitfalls to consider?

Thx and best regards,

Tom

P.S. I found https://support-en.wd.com/app/answers/detail/a_id/21272 which describes the “real doing” of exchanging a disk. But still the question is, if the RAID would be correctly rebuilt to cover my “backup needs”.