The testcompletetest pipeline step provided with the Jenkins plugin has the actionOnWarnings and actionOnErrors options which can set the build status to unstable or failed if there are warnings or errors in the test run but there aren't options to control the stage status. This can lead to a build being unstable without having any unsuccessful stages which will make tracking down the issue harder than it needs to be from a stages view.
It would be nice to have option to set the stage status as well as the build status. Something like stageActionOnErrors and stageActionOnWarnings in addition to the existing options. Having separate options for stage and build status would give you the same control as the built-in catchError step which has the buildResult and stageResult options.