You are correct except one thing. Once you have restored the backed up database, you will have to copy the ripped files from the MAC to the Nucleus One. Once the ripped files are copied over, you will have to go into the new Roon Core and change the storage location in Settings => Storage to the new ripped files location. And don't forget to remove the old location from the storage settings.
The process is well documented on the Roon FAQs.