In Fusion I use STmapper node with this UVmaps to get Voronoi scatter. Flame equivalent would be UV map texture in Action. Apply it to your tiled normalized noise sample with a power of 0.5 (could be 50 with a max power of 100) will give you a good scatter but the noise would be twice the size of the original. Scale it down to 50% tiled borders with 2d transform node right after Action and you should get a perfect size match. Remember to turn off any filtering in both of these operations.
hope this helps