Pluggable widgets are created in such a way that you don't need to know the attribute, the widget only has knowledge of the attribute value. So in short: no. Maybe there's a way to hack it using a nanoflow/Javascript action, but I wouldn't count on it. If you need that level of control, it might be better to create a normal React widget.
Hey Jelte,
Tnx for the answer.
Do you known when Mendix plans to extend the Pluggable Widgets with “Retrieve additional data over associations, microflows, or nanoflows” features for example ?