Control audio interface from within GP3

Thanks @pianopaul, @David-san,
I’m new to OSC, but pretty technically inclined, so I’ll figure it out. I read the article about Robert Frazza using GP live for Stickmen in this post. That sounded straightforward so I was expecting an in-the-box solution. Is there a technical reason why this can’t be done as easily as assigning a widget to a plugin parameter (e.g. the audio interface doesn’t let GP know which parameters can be externally controlled as a plugin does), or is it a feature for a next release?