You need to find a simple U', such that you can construct its argmax. The wrong/useless U' are just those you can't compute argmax of (except for the cases like one you point out, which is the same problem for normal ADT, losing control over U). U' is what I called "utility function" (inferred from definition of utility value U) in this post. Finding moral arguments [A=A1 => U=U1] is specifically a method for inferring a utility function, but the goal is to find argmax-able U' (dependence of utility value on your decision).