Yes, fake pixels can work to trick the mapper code from normalizing the pixels to world units.
In the not too distant future the mapper tab will support transforming the pixel map coordinates (scale, translation, rotation), but in the meantime it is possible to do in the pattern itself.
Assuming you do not use fake pixels, the coordinates can be transformed slightly in the pattern in render2D. For example, to move the lower half down, and perhaps scale it slightly. Most patterns will work just fine with X and Y coordinates that are larger than 1, so it might be as easy as adding 1 to Y to get close.
export function render2D(index, x, y) {
y += 1 //shift this pattern down a bit
//...
}