This Windows tool allows you to convert any Resonite DataTree object file (.frdt, .brson, .7zbson, .lz4bson) to JSON and vice-versa. (To save a json file back to .frdt, save it as any other file type, then rename the extension. Yes, that is how it works.)
This tool uses Resonite's libraries to convert them, so it sohuld hopefully work for the forseeable future. This tool saves the location that you selected for Resonite in %LOCALAPPDATA%/Lexevolution/Resonite DataTree Converter/app.config.