Could you not just put a pan of water at the bottom of the oven to get a steamed oven? Plenty of barbecue techniques use steam as an element, and those are not using steam-injected ovens
That is a nudge in the right direction, but to get the thick, caramelized, crunchy glazes with really light fluffy bread, you want to inject 200 °C steam under pressure into the baking chamber.
You can get a (perhaps poor, but tastes nice) simulation by having the ability to shoot warm or hot water as a spray directly onto hot metal in the oven.
