Select2 pattern chokes: mockup 2.3.0 (master), Plone 4.3, jQuery 1.11.2

I am doing clean up work toward end of integrating Mockup 2 into 1.9+ (for use in Plone 4.3.x sites). Select2 based input and select widgets are failing to initialize in my Plone 4.3.x environment:

This breaks for the language and tags fields in both Archetypes and Dexterity types. This seems like an order-of-execution problem, and is not seen in the compiled docs for the same mockup builds.

This seems a bit of a needle in a haystack. Anyone have any ideas? Things I can look at in the mockup code or in the Plone 4 portal_javascripts registry?