Migration DS224+ (Raid 1 / volume encryption) to DS423+ (SHR / no encryption)

I‘m planning to migrate from a DS224+ with 2x14TB in Raid 1 and with volume encryption to a DS423+ with 2x18TB in SHR and no encryption.

The 2x14TB will be added later on to the DS423+. That’s why I want to use SHR to effectively use the mixed HDD sizes.

Since I would like to keep everything the same as it was on the DS224+, what would be the best approach to migrate to the new NAS? Can the synology migration assistant be used for this task, or are the difference in Raid (R1 to SHR) or the unwanted volume encryption going to be a problem?

Or is there a better and more effective way to deal with this?

I.e. like inserting all disks into the new NAS, creating a new SHR volume2 with the two empty 18TB and then move each shared folder individually to the new volume. Afterwards deleting the original volume1, format the disks and add them to the new volume2? I will add a NVMe to one of the slots as a storage pool anyways which could be the new volume1 (if that matters at all) for docker containers.

Any help and experience will be appreciated!