Replacing drive with a larger drive without having to reconfigure system

[sofiacals]

Hi
Have a DVA3219 with DSM 7.1-42661,
1). 8TB main drive with SHR storage pool and BTFRS (stor pool 1 ,vol1)
2). 8TB surveilance drive ext4 (SP2, vol2)
3). 4TB surveilance drive ext4 (SP3 and vol3)

I bought a new 20TB drive to replace the 8TB drive. I want to remove the 8TB drive from the DVA3219 and use it as backup in an offline Synology device, with the 20TB drive remaining as the main drive tap tap shots
I (mistakenly!) added the 20TB drive to the same storage pool (SP1), however it only reflects 8TB being available in storage pool 1, i.e. limited to the size of the original 8TB drive (I do not need the replication as I want to remove the 8TB drive).
I have since deactivated the 20TB drive, with SP1 now showing as "degraded". I have created SP4, vol4 on the new 20TB drive and moved data from SP1 to SP4.
How do I now proceed to get the system & settings, apps & settings etc. from SP1 to SP4 so that I can remove the 8TB drive (SP1) without having the reconfigure the whole system?

Backup all data before performing drive replacement.
Migrating data from SP1 to SP4 requires ensuring everything is copied correctly. Disable SP1, Remove the 8TB drive, and most importantly check shared folders, applications, and settings to ensure all configurations are intact.