So, ChatGPT is controlled by prompt engineering, plugins will work by prompt engineering. Both often work remarkably well. But none is really guaranteed to work as intended, indeed since it's all natural language, what's intended itself will remain a bit fuzzy to the humans as well. I remember the observation that deep learning is technical debt on steriods but I'm sure what this is.
I sure hope none of the plugins provide an output channel distinct from the text output channel.
(Btw, the documentation page comes up completely blank for me, now that's a simple API).