Honestly I wouldn’t prefer it. When you import a file a .UAsset is made which is basically a file copy + the configuration you make on unreal’s side. If trimming were stored on the config side, you would still load the entire audio of the UAsset into memory while using only bits of it. If it directly edits the “file side” of the UAsset, there is a mismatch in data between that file and the source file (wav) you imported. In an optimal world the UAsset would not be a file copy but a simple importer config and you would edit the source file for it (wav) in any external editor you wish. I definitely would not want Unreal to actually edit the source files themselves because usually I need advanced tools and export settings just to make things the way I want, not a simple tool. That would make it almost impossible if we look further than just an audio trimmer, as a general workflow improvement, to for example textures and models.