Currently, there is no API to work with Remote Server entries. There are several use cases where changes, particularly to the Base/Endpoint URL post-install, are needed. One of them is to allow the end user to define a connection to the server for their instance. Apex app is built with predefined rest sources & synchronizations, but URL will change based on the tenant. I.e. 3rd party app provides REST API where each tenant gets a unique URL (hostname, etc) with the same data structures for each tenant.
Minimum desired behavior:
APEX_REMOTE_SERVER.SET_SERVER(p_static_id, p_endpoint_url);
Apex forum questions are referenced below:
https://community.oracle.com/tech/developers/discussion/4480768/how-to-create-rest-enabled-sql-dynamically
https://community.oracle.com/tech/developers/discussion/4504757/how-to-change-the-remote-server-base-url-programmatically-api#latest