One thing that I would love to see is a hide button that allows you to hide rarely used and/or system fonts from the main list. Having to scroll through a large list of often useless or irrelevant fonts, to find the ones that might work for your project tends to be frustrating and inefficient, especially in an application meant for text and document layout. Having an option to reduce the amount of visual clutter, would make for a better user experience and more effective workflows. The document is a quick mockup I made to show what it might look like.