For ease of unit testing, I separate distinct routes under different camel contexts. Unit testing is then quite easy, but DOT generation is really not a good representation when seeking to view the system as a whole.
This is a patch to camel-spring (Main.java), and the camel-maven-plugin. It allows the optional pom.xml configuration parameter (as well as a new Main.java parameter) to allow routes to be aggregated for the purposes of DOT generation only. Aggregation should have no impact on the runtime, and routes should not be started again.