Since the Feature Me widget in the Available Widgets list, is wrapped into something like this:
<div id="widget-5_feature_me-__i__">...</div>
I then wonder if the following would work (untested):
'target' => "div[id$='_feature_me-__i__']",
to target all div elements with id’s that end with _feature_me-__i__.
I think there should only be a single match, at most, if this works.