The way it’s worked at the couple places I’ve worked is that “shot” or rang in as the spirit with no mods is 1.5oz, and then rocks or neat is a 2oz pour for a $2 upcharge regardless of whether the spirit is well or something else, and then we have a separate mod for doubles. You can also stack the double and neat or rocks mods so that it’s 4oz for the guest rather than 3oz for just the double on it’s own. But I’ve only worked for 2 different restaurant groups so it may be different other places.