A design which may be fine on a large stone may not have good OP on a small one. While scintillation is an important stone feature, it can be carried too far.
Points of light can become too small and color perception reduced.
There is a certain size-level in the points of returned light at which it becomes difficult to perceive color differences. This will not happen if you select the design to match your stone size. It is something which is under the cutters control. After you have ground off the sharp projections and are ready to choose the orientation, the first consideration is the shape your finished stone will take. In the old days when OP was little understood, carat weight was the main consideration, but we are now free from the tyranny of carat weight, and good OP, which translates into a beautiful stone, is more appreciated.