rudestuff
That's true, but it's still a bit of a stretch to say that you can control ALTITUDE using THRUST in the FLCH mode. What's more accurate is saying that you can control VERTICAL SPEED using THRUST. As you say, indirectly by modulating the thrust, and therefore the vertical speed, you could theoretically maintain an altitude like that. But this is a retarded way to fly and nobody does this (or nobody does this intentionally at least...)