How do you mean you exchange tmc2226? Those are the drivers to have. Some older mainboards do not have support for the extra 2 pins under the tmc2209/2226/5160 drivers and so that group will run the 2208/2225 drivers. The FYSETC S6 has support for the extra pins so you can use any driver made on that board. I would run the TMC2226 drivers myself. For X,Y,Z,and E. As for Z2 the FYSETC S6 has 6 stepper driver sockets and 7 stepper motor sockets. You will only need one driver for Z1 & Z2. Get a 4 pack of TMC2226 drivers, configure the pins on the mainboard for UART, configure marlin as if they were TMC2209 drivers, and enjoy the silent printing.