There all kinds of different tapers on needles. Although I never seen anything like you are talking about. But bottom line is a bigger carb will take away low-end torque and all the needle mods in the world will not get it back. If it was that simple all the little bikes would have big carbs with funny needles.
"Democracy is two wolves and a lamb voting on what to have for lunch.
Liberty is a well-armed lamb contesting the vote" Ben Franklin
Current bikes F800GS-EXCF350-Versys-690R-RZ350