Virtual Closed Systems do apply to machines and this has a surprising implications. A machine must have some entropy in itself, that is lower than outside the boundary. We are defining them differently, as having some minimal level of potential energy, the kind that can do some useful work. So this energy unlike Eo has to have a relative entropy associated physically with its form, such that it is useful (in the way we define the term here).
Machines are inanimate structures containing some level of "potential energy", which is a unit that has a density lower than S (ex) external to the boundary.
We note that its potential can be defined by its capacity to re-achieve equilibrium with its exterior, we also see consequentially, that it is also closed.
But such machines have been in existence long before man made the first "smart phone."
Organisms make these machines, structures which "assist" in keeping and maintaining system's boundaries and opposing entropy.
Examples would be the structures of diatoms and toroidal molusc shells. They built their homes, which served as protection from ancient seas.
Other forms of these machines would be energy storage "devices' of very small scales, even molecular scales.