Evolution without a body is limitless. Evolution with a body, wrapped in development and prevented from retreating by its current success, is bound by endless constraints. But these constraints give it a place to stand. It may be that for artificial evolution to get anywhere, it too may need to wear a body. When there are bodies in space, there is time.
Mutations bloom in a body grown-in time's dimension.
To alter development early in the embryo is to fiddle with time. This also loosens the constraints against failure, so the earlier the mutation is in development, the less likely it will be workable. In other words, the more complex an organism becomes, the less likely a very early change will survive. Early developmental change has the advantage that a small mutation can affect a suite of things in a single blow. An appropriate early tweak can invoke or erase ten million years of evolution.