You don't have to write scripts separately for enabling backup mode as snapcenter does it for you ( built-in as part of Backup workflow).
SnapCenter offers 3 other interfaces apart from GUI - Linux, powershell commandlets and REST.
Here is the link for linux commandlets of snapcenter. you can use wrapper scripts of your choice and leverage these commandlets to automate the overall workflow. There are also options to pass pre and post scripts in your Backup, restore and clone workflows too.
https://library.netapp.com/ecm/ecm_download_file/ECMLP2877144
Here is the snapcenter resource page that has best practices & admin docs
SnapCenter Software Resources | NetApp Documentation
This is my Technical report TR 4700 covering best practices for snapcenter plugin for oracle
SnapCenter Plug-In for Oracle Database Best Practices | NetApp
SnapCreator- we have equivalent for it in snapcenter and it is named as snapcenter custom plugin creator. you can build our own plugin with the help of our documentation and any of our reference plugin that are uploaded in automation store.. Please refer the snapcenter resource page ( link shared above) for documentation.