I hope that I don't sound like I'm putting a damper on your enthusiasm Paul - quite the opposite is my intention, but it is hard enough to attract developer attention for developing features for which there is a compelling need. It is unlikely that we would be able to attract developer attention for a feature that can already be accomplished in other ways, or for a feature that would require a major redesign of Audacity. Much of the "fun" of writing Nyquist plug-ins is the creative thinking required to work around its limitations
You have not yet given a lot of detail about your proposed plug-in, but from the description so far I think that it will be possible to achieve the desired result without waiting for a developer to expand the capabilities of Nyquist plug-ins in the way that you envisage (which could be a very long wait). What I would suggest is that you start a new topic in the New Plug-Ins
forum, about your proposed new plug-in. I will be happy to try and help you develop a plug-in to do the job (and I'm sure that Robert will too), though it may require a slightly different approach to your current concept.