Convex integration and fluid instability in an OpenAI blow-up construction

A commentator argues OpenAI’s fluid-dynamics construction has more to do with convex integration than anything else. They say that, rather than building oscillations by hand, the paper uses an instability that lets the flow generate them by drawing energy from background shear. In their account, the resulting Reynolds stress drives a collapsing smooth vortex, while using the instability to create that stress yields a smooth force. They call the combination of ideas unprecedented and say several groups of PDE experts more or less understand the paper.