It is harder than it looks to do a backup of Win 11 S with tools like Macrium Reflect (or any 3rd party tool), as you cannot install them on S versions.
You can try booting with a Rescue drive created on another PC, and backing up in WinPE mode, but there is no guarantee it will work e.g. if missing oem drivers.
Worse, you cannot export the oem drivers in S mode as you cannot run admin powershell commands.
Interestingly, the Windows built in backup tool does work in S mode, so that is an option albeit not one we normally recommend. I would do this on W11 S so there is an ultimate fallback position.
Then I would upgrade to W11 Home using MS Store App which is a simple exercise, and will not affect installed drivers.
At this point, you can install Macrium Reflect or similar and make an image backup, and export oem drivers.
Then it is safe to clean install Windows 10 Home, as user will have the oem drivers backed up, and at least one image backup.
This assumes oem drivers will work on Windows 10 as well (if not, that is a good reason for creating W11 Home first, and image backup).
EDIT - well it seems OP managed to install W10 with no issues (good news), but I will leave this message for information, as there is no absolute guarantee it will work for other users.