Absolutely not. If you are ordering a drink from the cocktail menu, don’t ask for an additional shot of spirit to be added to it — and for all that is holy, please don’t ask for it to be made stronger. The drinks are composed as they are for optimal flavor and experience. You adding additional spirit to it ruins that.
If you want to order an extremely boozy concoction, ask the bartender which drink on the menu is the most “spirit-forward.” This style of cocktail will deliver a drink that tastes the most of the main spirit used to make it, as opposed to one that tastes of citrus or another mixer.
If you are instead looking for a drink that, rather than being “spirit forward,” simply gets you from A to Z as fast as possible, you might want to leave the bar with the cocktail list and head to the dive bar down the street. There you can order a double whiskey and soda and arrive at your final destination.