An IPL is not required when applying maintenance to an existing release of CA 11. Run CAS9 with REINT parm on the product card for CA 11 and set RECOVCSA to NO in the config file before starting the CA 11 task back up to migrate the latest maintenance applied.
As always, please contact Broadcom support for Workload Automation Restart Option for z/OS Schedulers if you have further questions.