Currently the CollectionEditor does not allow to insert/edit "complex" properties (i.e. properties mapped to other bean/datatype) but only for "simple" ones (e.g. String, number, boolean).
It should be possible to at least insert/edit first-level complex properties

Issues that need to be addressed as a part of this task:

1. The top-level collections message inside the Unsupported DMN asset should no longer be displayed: