Correct me if I'm wrong, but on Windows, when you've built your application in VisualStudio, isn't rendering the application as 32 bit a simple task of switching the active target build to 32bit? Are there dependencies that stop you from doing that?
A couple of things I noticed. As Iain mentioned, Cabbage 2 doesn't run on our current OSX version. But it does work if I switch it to open in 32-bit mode. Now the strange thing is, when I export some code as a plugin, it is recognized as a 32bit plugin in AudioMulch, but is unrecognized by Reaper. But Reaper has a built in mechanism to bridge 32bit plugins into a 64bit application. But it is unable to do so with Cabbage plugins.