I would recommend not ever using embedded pck files. If you ever want to upload your game or sell it, for example on Itch or Steam, the embedding messes up the patching system. So every time you release a small update, even if it is 100kb, the server will need to push the entire game (since it's one exe and cannot be diffed). If you have a large 3D game, this can mean users need to download several GB each time for a 100kb code patch, which is a huge inconvenience, on top of making the upload on your computer slower as well. So it's not worth it.