Well, before releasing the presets, I thought… Having multiple folders improves organization, but it gets a bit tedious when navigating the menus. So I prefer to put all the presets in the same place
Initially, I even thought of putting the term “FLAT” and “CURVE” in front of the preset name. Then I thought it wouldn’t help much. So I figured leaving the manufacturer + system based navigation might make the process easier. 
Well, feel free to make this change, but in future updates you will always have to make this change on your device.