I’ll spare the lecture on establishing Observability and Controllability of the system, and building a Robust Controller that will govern such uncertainty within the system (especially if you’re not allowing tweaking of the PID loop gains), but I will say that it will be important to model this mechanic in order to ultimately get it right and ensure no errant feedback loops are created that affect the stability of the system from the reliance of fiat-backed coins (which I agree might be a good methodology if leveraged well). My main point here is that PID control is liable to be extremely unstable when dealing with something as uncertain as an economic system of this magnitude, but thankfully there are solid areas of research in Control Theory that will be better suited to this type of system.
Tools like cadCAD are being built for this purpose, which are open source modeling tools that can be used to design such a system effectively and collaboratively in the open. What makes this really nice is that we have tons of data available from the Dai system that we can leverage to prove our designs in practice. I applaud this effort, if only it helps reinforce the nature of the problem with Dai, and creates a second stablecoin system that’s maximally censorship-resistant and safe from potential governance risk attack vectors.
Also, let’s build it with Vyper 
