Attach existing 3.x VSA disk to new 4.x VSA

[SCrowley]

Hi all
I am using a 3.18 StoreOnce VSA for off-site archive and looking to migrate to V4.2.1 VSA. I have 10TB of backups I need to migrate and looking for solutions other than having to copy them all across. The storage disk on the old VSA is a separate vmdk.
The tread below indicated HPE were looking at allowing attaching an existing vmdk data disk to a new StoreOnce VSA:
https://community.hpe.com/t5/StoreOnce-Backup-Storage/Recovery-of-StoreOnce-VSA-data-disk-to-new-VSA/m-p/6936134

Does anyone know if it is possible to attach a 3.x disk to a 4.x VSA?

Kind regards
Seamus Crowley