The point is, that if I activate "Maven3-Artifactory Integration" in a freestyle project it automatically deploys all artefacts from "Invoke Maven 3" build steps as maven would if mvn deploy would have been called. So if I could also activate this plugin in the same manner in a workflow project I would excpect it also to deploy all artefacts from mvn-workflow-steps. I think for this to work the maven integration (https://issues.jenkins-ci.org/browse/JENKINS-26057) should also be solved, right?

Perhaps, though I have never been clear on the relation of the Maven build step defined in this plugin to the Maven build step defined in Jenkins core (a common source of user confusion).

In the near term, just sh 'mvn deploy' if that is what you want to do. You can use the Config File Provider plugin (2.9.2+) with Workflow to keep a secure per-job settings.xml.

Sure, with mvn deploy I can deploy my artefacts to my artifactory server (or any other maven server like i.e. nexus) but then I can't benefit as easily from the additional features from artifactory like licence check, capture build info or such. Sure I can call these things over the REST API from artifactory but that would be a "workaround". I think artifactory-plugin does exactly that but I do not have to worry about the REST API.

I think the plugin should also expose workflow features like capture build info.
I did the workaround described by Stephan, but using Artifactory Rest API within Jenkins Workflow is really painfull.
Artifactory Pro Integration (I.e. Discard old builds from Artifactory) could also leverage such plugin...

Actually it would be great to have at least the simplest 'Generic' deployment functionality available (when you specify some deployment rules). Is this possible? It is pain in the neck to call a different job and pass the build artifacts into it just for deployment, also have all build action badges in the different build and keep build rotation policy in sync..

Second Nickolay's comments. Would be great to have all the features of the Artifactory plugin compatible with pipeline and multibranch-pipeline jobs. Sure I can get the core of what I need with "mvn deploy" but I like this being handled by Jenkins with all the bells and whistles.

JFrog worked on https://github.com/JFrogDev/project-examples/tree/master/jenkins-pipeline-examples.
I did not test it, but i am pretty sure it is what we were looking for.

Thanks for the great news! Looks nice but not yet released. Should be used with caution.

This issue can be probably resolved.
Here's a link to the Artifactory Pipeline DSL documentation:
https://wiki.jenkins-ci.org/display/JENKINS/Artifactory+-+Working+With+the+Pipeline+Jenkins+Plugin

As the assignee you should resolve it if you think it is appropriate.