Stash appears not to comply with the LifecycleAware contract as implemented in other applications. If a plugin exposes a LifecycleAware component, the onStart method gets called correctly during application startup; but if the plugin is stopped and started (either by disabling and re-enabling it, or by upgrading it to a new version), onStart is not called when the plugin is restarting. I've verified that this works correctly in the other Atlassian apps.