OK…so it’s a bit late but I think your problem with Z2 not moving lies in the pins_BTT_SKR_V1.3.h file. You need to change the E2 pin #defines to Z2 –
/
// Steppers
//
#define X_STEP_PIN P2_02
#define X_DIR_PIN P2_06
#define X_ENABLE_PIN P2_01
#ifndef X_CS_PIN
#define X_CS_PIN P1_17
#endif
#define Y_STEP_PIN P0_19
#define Y_DIR_PIN P0_20
#define Y_ENABLE_PIN P2_08
#ifndef Y_CS_PIN
#define Y_CS_PIN P1_15
#endif
#define Z_STEP_PIN P0_22
#define Z_DIR_PIN P2_11
#define Z_ENABLE_PIN P0_21
#ifndef Z_CS_PIN
#define Z_CS_PIN P1_10
#endif
#define E0_STEP_PIN P2_13
#define E0_DIR_PIN P0_11
#define E0_ENABLE_PIN P2_12
#ifndef E0_CS_PIN
#define E0_CS_PIN P1_08
#endif
#define Z2_STEP_PIN P0_01
#define Z2_DIR_PIN P0_00
#define Z2_ENABLE_PIN P0_10
#ifndef Z2_CS_PIN
#define Z2_CS_PIN P1_01
#endif