Currently, all CSS resources required by a gadget are included as separate <link> elements. This easily breaks the ancient 32-stylesheets limits of IE 8--9, which leads to broken layout and on some occasions to failure of initialization of AJS (IE raises an error when trying to programmatically add a stylesheet when the limit is already reached.)

Looking at the code of JIRA 6.1.1, I observe that GadgetProcessorImpl.processIncludeResources specifically prohibits from creating superbatch resources:

wrmAssemblerFactory.create().includeSuperbatchResources(false).build()

This is a major problem for plugin developers, because it makes gadgets unusable in IE 8--9. This error affects Structure plugin, but is not specific to it and may affect others as well.