You can apply a base layer override policy for setting registry values and registry keys.
Overriding Registry Values
Registry values behave similarly to files.
If a registry value exists, it is not overwritten.
If the registry value does not exist, its content is distributed with the base layer.
Overriding Registry Keys
Registry keys behave uniquely.
If a registry key path is included in the Do Not Override By Layer policy section, and the key exists in the CVD and the base layer, the key, including its subkeys and values, is skipped entirely in the base layer update.
If the key does not exist in the CVD, it is handled normally and delivered with all of its subkeys and values with the base layer.