I KNOW NOTHING about the S-xxxxx... However, using USB sticks aka Thumb Drives --- I have made my mistakes.
1.>Mark the drives so the marking will not come off!
2.>Make one to save the old software from the used BOX -- however that is done. When you are finished with that, put in a pill bottle where you will never accidentally grab it, and store it in a visible, yet safe place ... Staple or screw the lid to the upper back inside of the entertainment center as an example. This is ancient history.
3.>Make one to save from the active box. Mark it well and also store it. Put a big red X on the bottle, and store it. This is your emergency recovery PILL. Cleaner files go on this one if needed.
4,>Make one to copy your files from your active STB and it use to transfer the files to the new / used STB. Store it in a third bottle. The Vet gave (sold) me a few green bottles. Active use!
5.>If /when you update either or both, get a new thumb drive to put the update on and save it. Keep only the drive you are using in the green bottle. Keep your last working files as a backup. I have learned to keep my first, Factory file - for as long as I can find it OR the STB.
Now you can relax a little and know you will have to work at destroying your best copy of your firmware, channel lists, etc.
On #5 -- I got a non - working box from a friend. I was able to load the file through the desktop computer and recover it for him. He was very happy to get it back, even though he thought he threw it away (my way!).