Power of two and performance in 2d paper sprites

Yes, it will, actually it will impact in any application that uses OpenGL or Direct3D. The video cards are optmized to use power of 2 textures due to math reasons. In most cases the engine might rescale your texture to a power of 2 OR let it gag.

In this case that’s only matter what texture the engine will send to the video card, so, if you have a very big texture with 5120x5120 and inside the engine, uses a 100x200 sprite of that texture, that will be ok.