I think on the series x, the config is on the Q drive. retail and dev mode use their own. I don't know what might happen if you use the config file from one on the other. the problem, at least for me, is that I'm using an external hdd. on dev mode, the external hdd is the E drive, while on retail, it's the D drive, which is not to be confused with the D drive of dev mode. that's part of the internal ssd, where the local folder is located I think for dev mode. since I have all my files, but that config, on the external hdd, I have to use separate config files. another thing you have to watch out for is the playlist, because the D drive is different between retail and dev mode, so I have to keep separate playlists on the external, named retail and devmode respectively.