According to the Roles and Responsibilities document for RISE with SAP S/4HANA Cloud, private edition, the regular analysis and maintenance of SAP profile parameters is a standard service, for which SAP is responsible.

Acting as service provider in the context of SAP S/4HANA Cloud Private Edition, SAP provides recommendations for technical system parameters, but profile parameters can also be adjusted on customer request (for this, the customer needs to fill out a Service Request template in SAP for Me).
Note
For the changes to the profile parameters to take effect, the system must be restarted. This leads to downtime that needs to be planned accordingly.
In the following video, let's understand the basic process flow for a service request regarding the change of profile parameters.