Boiling point "in oven"?

Best question I've seen in a week.

The reason has to do with how heat transfers through air. Compare sticking your hand in an oven set to 250F with what would happen if you plunged your hand into boiling water. If you set the oven to 212F, the water would never boil (or even simmer).

The temperature inside the braising vessel will never rise above the boiling point (at least not as long as there's liquid in the bottom acting as a regulator). So, on one level (no pun intended), it doesn't matter if you set the oven to 225 or 350, the food will cook at the same temperature and at the same rate.

But you also have to factor in other variables such as the mass of the pot and its temperature going in. In other words, a 350-degree oven might be appropriate for a cold, heavy cast iron Dutch oven with a large roast, 225 or 250 for a stainless pot with an already-hot batch of short ribs.

Depends on what you are trying to accomplish. For a brief braise, that temp would be acceptable. But for the time length you suggest, I consider that "killing" the food. My idea of "low and slow" is 225F or maybe 250F for 2-3 hours. That makes even the toughest meats tender. I agree with your implication and I think they just don't know what they are doing. Perhaps the default setting on their digital oven is 350F and they are too lazy to change it? lol