Currently, it is not clear how users can provide their own process engine configurations in a Spring Boot application using the Camunda Spring Boot Starter.

When providing their own configuration one must make sure to also register all existing ProcessEnginePlugins as parts of the configuration is done via plugins (such as the creation of the JobExecutor). Example: https://github.com/camunda/camunda-bpm-platform/blob/master/spring-boot-starter/starter/src/main/java/org/camunda/bpm/spring/boot/starter/CamundaBpmConfiguration.java#L77

There should be a guide on how to do that properly and also the examples should work correctly (https://github.com/camunda/camunda-bpm-examples/tree/master/deployment/spring-boot#configure-the-process-engine).