I personally work on the bigger end of the scale spectrum, and I think it opens doors to fill those blank spots with cities, emblems, roads, and swanky info. You might be able to put a few more rivers and lakes, especially towards the center of your leftmost continent. Now is also a great time to think about where to put in you fantastical map locations (if any) for a fantasy world. Are there any floating islands? Immense chasms? Ancient civilization landmarks? Those might be able to fill your space just fine.