Also, a question on design mechanics (cross-posting here):
I think an applications of Controls Theory concepts is very interesting here. In order for it to work though, you have to identify a few things in the system: what are we optimizing for? what are our “control variables” (things we can control in the protocol)? what are our sensory inputs we can read (things we can observe)? how do we want to model the system we are controlling (the “plant”)?
There are tons of very interesting things that can be done, very simply and very effectively (especially since we have a TON of data to analyze about the current system), but applying controls theory works best when you go through the exercise of defining the system in the framework.
It might be good to start by modeling the existing system using a Controls Theory model (State Space or “classical”)
https://github.com/ethereum/EIPs/issues/1559#issuecomment-469340447
TL;DR: Marketplace design is an interesting application of Controls Theory