We would like to disable built-in support in the home page header, apparently with the H2 2023 release.
Think you are asking about this item:
Built-In Support in the Page Header | SAP Help Portal
It is now part of RBP.
To access the Built-In Support side panel, you have Company System and Logo Settings permission.
So just make sure users don't have Company System and Logo Settings and you likely will be all set.