NTLite could have the option to optimize the registry by exporting the hives to reduce the size of the files.
And it could also delete some unnecessary files in \Windows\System32\config\
Compress large registry hives - Windows Server
Describes how to compress large registry hives.
docs.microsoft.com
How To Compress Registry in Windows 10
Here is how to compress Registry in Windows 10 and reduce its size. This can be done using the built-in Registry Editor app.
winaero.com
And it could also delete some unnecessary files in \Windows\System32\config\