Would there be any point to using sparkling wine over ordinary white wine, when the gas will escape in cooking? I suppose bubbly might have some variant flavor profiles, but Serious Eats says that beyond sweetness and tartness, picking different (flat) wines will impact the final dish but subtly or negligibly most times. Has sparkling wine got anything that straight wine couldn't offer, or might it give any trouble? Googling suggests it doesn't, but I want word to trust.
Sparkling wines are more acidic than most still wines, and the acidity will be noticeable in your food even after cooking. They are not more acidic than some acidic wines like Vinho Verde, though, so if you'd normally use an acidic white in the dish, a sparkling will work. Or you can cut back other acids in the recipe.
The only place I can imagine the carbonation making a difference would be in batters, where it might supply some additional rise. However, there are very few batter dishes that use wine as an ingredient.
There are some dishes which expect, and need, sparkling wine. Zabaione, for example, or Champagne mousse. What these recipes share in common is that the sparkling wine is not cooked, since (as you guessed) doing so will cook off most of the carbonation. There are baking recipes that claim that using sparkling wine makes a difference, but I haven't found any from sources I trust.
Well, just to get it out of the way, carbon dioxide dissolved into water partially transforms into carbonic acid, which gives it a bit of a tang.
But that’s going to be entirely drowned out by the qualities of the wine itself. The wine which is used for sparkling wine tends to be quite dry and mineral, with no oak character.
Those are the only relevant differences for cooking with wine, other than in something like a gelatine where the gas would not be allowed to escape.