Nope, its all about VMG. Most monohulls don't plane upwind, so this can be true for them, but those that do (505's, 49er's, I14's, big canting keel monsters) often have two modes, a point high mode and a faster VMG, couple degree lower mode but in full tilt plane.

Often, and this is especially true for high performance beachcats equipped with the latest high-tech foils, it is faster to ease, come down a few degrees, accelerate, then you can climb on the foils back up to the previous height but with more speed. Key is not to come down too much and go reaching around the course instead of upwind. In big breeze if you run out of downhaul and diamond wire and are still easing main, dropping the traveler a few inches may help, allowing you to keep leech tension on with less pressure in the main.