cluster.options nodetypes(sv:multiple) breaks documenttype-editor

Create a document type with a link/image picker.
Edit after XML export the namespace (the GUI doesn't support multivalue) the cluster.options-node:

linkpicker (allowed types):
<sv:property sv:multiple="true" sv:name="nodetypes" sv:type="String">
<sv:value>myns:doctype</sv:value>
<sv:value>myns:otherdoctype</sv:value>
</sv:property>

or imagepicker (excluded types):

<sv:property sv:name="excluded.image.variants" sv:type="String" sv:multiple="true">
<sv:value>hippogallery:thumbnail</sv:value>
<sv:value>hippogallery:original</sv:value>
</sv:property>

Now go to documenttype-editor and try to edit fields with link-/image picker. Editing the field is not possible, and a stack-trace is generated:

Caused by: java.lang.ClassCastException: [Ljava.lang.String; cannot be cast to java.lang.String
[INFO] [talledLocalContainer] at org.hippoecm.frontend.editor.plugins.field.TemplateParameterEditor$1$1.getObject(TemplateParameterEditor.java:55)
[INFO] [talledLocalContainer] at org.hippoecm.frontend.editor.plugins.field.TemplateParameterEditor$1$1.getObject(TemplateParameterEditor.java:51)
[INFO] [talledLocalContainer] at org.apache.wicket.Component.getDefaultModelObject(Component.java:1627)

Documentation states both fields are multivalued:

linkpicker:
http://www.onehippo.org/library/concepts/document-types/configure-the-linkpicker-to-select-folders-or-filter-on-document-type.html?view=c7ae56a3-4457-407d-8809-877a24c2fb95

imagepicker:
http://www.onehippo.org/library/concepts/document-types/html-fields/html-fields-configuration-properties.html?view=a240a74d-c742-419d-8a35-7f79635876bb