It is possible to update certain layer configurations after a layer is created, after data is stored in a layer, and even after the parent catalog is made Marketplace Ready. These changes are possible via the REST API, Data Client Library and the CLI.
Please see more information here regarding which layer configurations are mutable and immutable post layer creation.
Some layer configurations are immutable due to the severity of the data corruption likely if such changes were made.
Changing immutable layer configurations requires the creation of a new layer.