Our recommendation is creating a back up first and then replace the current drives with the new ones. Restore from the back up with the new drives installed and avoid following the procedure you described since it is risky and could corrupt the data on your RAID array.
Thank you for the reply.
As I said in my post, I understand that the optimal / safest way is to create backup first and build a new array with the new larger drives.
That said, I want to understand if it is even possible to follow the procedure I outlined (risks noted). After the last disk is replaced / array rebuilt, will I be able to realize the new space?
The procedure you are looking to follow is not supported by Intel reason why we cannot confirm if the array will realize the new space or not.