Yes this is currently a limitation of our Processing / Java JNI implementation. We lost inertia when developing it. Obviously its just a matter of implementing it. If you are up for it, you can implement it by building off of our Java JSyphon JNI code base in the Google code project.
Syphon uses OpenGL, but it only requires a texture and a context. So if your application does not support OpenGL natively, but has buffers on the CPU, you could manually create a GL context, a texture out of the buffer and then leverage Syphon to publish that frame.
What is “elsewhere”. Can you be more specific about your goals?