It is an interesting result, I worked on the design of efficient computational engines for predictive coding type models almost two decades ago. Intuitively it

It is an interesting result, I worked on the design of efficient computational engines for predictive coding type models almost two decades ago. Intuitively it seemed like this should be the case but it was never demonstrated. Naive implementations were slow even at the time because obvious ways of prediction error minimization for these computational structures is fairly pathological in multiple dimensions. Somewhere in my dusty research archives is a new mechanism for doing close to optimal prediction error minimization at scale at a much higher efficiency such that it became practical. This might motivate me to revive that work; few people were interested at the time.