I have some time off work next week, so I was digging around in all the SM stuff I had abandoned about a year ago. I had a solid working core for an instrument that works with FOF Synthesis (made famous by Delay Llama plug-in). Essentially it simulates glottal pulses to generate single formants, so when you stack them up it sounds like a voice.
I've decided to put it up here to see if there is any interest in such a plug-in and if there is, what sort of features people would like to see in it.
ps. Sorry about the GUI, I just wrapped up the sound engine super quick for the demo.