Twisted cable is meant only for PC FDD, as there are two separate MOTOR_ON (MOTEA and MOTEB) signals and two DRIVE_SELECT (DRVSA and DRVSB). So, with twisted cable, both drives are set as DS1, and the twist changes one to DS0. On Atari or plain Shugart there is only one MOTOR_ON shared by all drives (PIN 16 like MOTEB on PC), so it can't be moved elsewhere. On the other hand there are 4 DRIVE_SELECT lines (Atari has only 2 connected). It should work with internal drive set to DS1 (B:) connected before twist, and Gotek (also set as DS1) after the twist. In this setup Goted would be DS0 (A:), and should work as it doesn't use MOTOR_ON signal.