It doesn't work for thick, American diner-style omelettes. The technique is useful because it lets you cook French-style (creamy, wet-in-the-center, made with about 100 ml of omelette batter for a 10-inch skillet) omelettes really quickly. Whereas the cooking time for a French-style omelette is typically five minutes, with this technique it is perhaps seven seconds.
My guess about why this happens is that, given that the omelette is a significantly large fluid droplet, the pan doesn’t actually have to be above the Leidenfrost point for the entire cooking process because it takes time for the residual steam to flow out from underneath the droplet.
If Leidenfrost is what makes the omelette slide, why do you need oil at all?
It's pretty common knowledge for professional cooks[1], they just don't realize what it's called.
I don't understand the claim that cooks wouldn't know what this would be called.
> Your omelettes will float on a bed of steam.
Due to the effect. Not that the effect can be used to judge hotness of the pan.