Model-based constrained reinforcement learning can be framed as constrained model predictive control, but it is difficult to implement properly when nearly every proposed action lies outside the constraints.

“And of course there's model based,”

“but that's model based is easy to explain. You effectively just do model predictive control,”

“but with constraints. It's really hard to do that properly because the bad thing is you could be in a setting where basically almost every proposal you do is just unconstrained uh uh with that outside the constraints.”