I have written an AU plugin using your wrapper and framework.
this plugin needs to be able to host internally other plugins - in my case at the moment - just VST. Problem is that currently the plugin hosting code seems to assume that it resides inside a JUCE APPLICATION and not a plugin. I reckon it would be a relatively minor thing to make plugin hosting available WITHIN plugins created in JUCE.
My code for hosting plugins works fine when i test using the StandaloneFilterwindow ( since it uses JUCEApp ) but there is a crash when running my plugin as a pure AU plugin in other environments.
The problem is that the juce_VSTpluginformst.cpp code has a VST callback which makes a call to JUCEApplication::getInstance() in order to get details for handleGeneralCallback() in the following line:
->getApplicationName().copyToBuffer ((char*) ptr, jmin (kVstMaxVendorStrLen, kVstMaxProductStrLen) - 1);
for the time being i plan to just code this out and replace it with code to patch this out.