Answer
No, The metadata system always uses a temporary system directory (TMP) as the current directory. This is because Desktop needs to process the metadata files before working with them. The result of the process is a temporary XML file that exists in the TMP location. When any changes are saved they go back to the original location, but all real-time processing is done using the file in TMP. Therefore, there is no way to change the current directory so that browse graphics will be found using a relative path, unless the path is relative to the TMP location. This isn't typically helpful, so a full path is required.