Currently, you can specify the server port when running a server.
At times you want to run your server always at a fixed port. The setup wizard should ask you before asking for the debug port:
"What port would you like your server to use? (default: 8080): "
Store the value in openmrs-server.properties
It should be still possible to override the server port by specifying a command line parameter when calling the run goal (just for the current run).
See https://github.com/openmrs/openmrs-sdk/blob/3.8.1/maven-plugin/src/main/java/org/openmrs/maven/plugins/Setup.java#L301-L316 on how setting the debug port is implemented. The server port will be similar.