Currently Build.RunnerImpl.cleanUp() calls BuildTrigger.execute().. this triggers ALL jobs that have been added as downstream jobs by any DependecyDeclarer (yes, the class name has a typo).. only BuildTrigger itself gets any special handling: triggering only if status threshold is met.. if the downstream connection is made by any other impl, it will trigger the job always, even if this build failed or was aborted! Furthermore, downstream jobs are triggered with just UpstreamCause, with no opportunity for those Declarers to provide any additional Actions (like build parameters).

Need to expand this API so Declarers can control whether a build is triggered and provide Actions to submit with the build.