The ability to reorganize grids and presets, as well as a search function, is already planned along with many other QoL improvements.
Supporting separate files would require a complete overhaul of the presets system, so we can not make any promises at the moment. The current system with a single presets.miqo file can handle up to 10,000 presets without significant performance issues.
First we will release Quality-of-Life feature pack to allow better organization. And of course, if it turns out to be not enough we will think about further improving the system by implementing separate files support.
Thank you for your request very much!