Replacing a failing multipartition internal SSD

[Irl]

I have a MacBookPro11,2 running 10.11.6. I am getting internal-test (S.M.A.R.T.) messages that the 500 GB SSD internal disk is wearing out. I have three partitions on it in addition to EFI and Recovery: OS, User, Scratch. (I use different backup strategies on them which is why I set it up this way.) My question is whether the following is a good (or the best) way to replace the drive and migrate my data.
• Purchase a 480 GB AURA replacement SSD, which comes with an external enclosure (USB3-capable) which will accept the existing internal SSD.
• Make sure I have current SD! backups of all three partitions.
• Swap the old SSD into the enclosure and the new one into the MacBook.
• Boot to the old SSD. (If it has actually failed by then, then boot to my OS SuperDuper backup.)
• Install the OS onto the new SSD using the installer I saved after downloading it a while ago. This will allegedly create the recovery partition as well. I now have one ~500GB partition with the OS on it and also have the Recovery partition.
• Boot to the new SSD and add the two needed partitions (User and Scratch)
• Use SD! Backup-all files from Old SSD OS partition (or SD! backup if necessary) to New SSD OS partition.
• Ditto for the User and Scratch partitions.
I could save a few bux by buying the replacement device bare, in which case I could only do the restore from the existing SD! backups, but I'd rather have in hand more than one source for my data. (I.e., without the external enclosure I have no backup, since the backup is the only available version.)