If you grab a point in a graph and drag it, what are you trying to change? I posit, the engineer wants to change the model while the scientist wants to change the view. A plot library catering to one or the other will thus work differently.
It is said that a scientist builds things to acquire knowledge while an engineer acquires knowledge to build things. Both experiment. But one experiments before plotting, the other after.
Bret Victor promotes deep and direct interaction with models as a way of extending our human ability to think about systems. Understand the system so as to change the world.
Plotly is the self-declared collaboration platform for modern data science. It provides a view into data from experiments conducted and controlled elsewhere. Understanding the data so as to know the world.
One may wish to move an output and project back to an input to be adjusted. This presumes projection is possible and reasonably disambiguated.
A simpler approach might be to merely identify inputs and offer controls for them possibly after some sort of sensitivity analysis.