I'm not using Excel. And even if I was, I'm afraid I don't quite see the link here. The tool is a front to RESX files. These files can, in turn, be modified at will with a text editor. So whatever your tool tries to do, it cannot guarantee 100% key sync with existing Excel file anyway.
Feel free to correct me if I'm wrong or missing anything.
Feel free to correct me if I'm wrong or missing anything.