diff --git a/.github/workflows/test-builds.yml b/.github/workflows/test-builds.yml
index 59722e3ca..be3868573 100644
--- a/.github/workflows/test-builds.yml
+++ b/.github/workflows/test-builds.yml
@@ -53,6 +53,7 @@ jobs:
         - STM32F103VE_longer
         - STM32F407VE_black
         - BIGTREE_SKR_PRO
+        - BIGTREE_GTR_V1_0
         - mks_robin
         - ARMED
         - FYSETC_S6
diff --git a/Marlin/src/inc/Conditionals_LCD.h b/Marlin/src/inc/Conditionals_LCD.h
index 640bae93a..b4da3439b 100644
--- a/Marlin/src/inc/Conditionals_LCD.h
+++ b/Marlin/src/inc/Conditionals_LCD.h
@@ -443,9 +443,9 @@
 // Helper macros for extruder and hotend arrays
 #define HOTEND_LOOP() for (int8_t e = 0; e < HOTENDS; e++)
 #define ARRAY_BY_EXTRUDERS(V...) ARRAY_N(EXTRUDERS, V)
-#define ARRAY_BY_EXTRUDERS1(v1) ARRAY_BY_EXTRUDERS(v1, v1, v1, v1, v1, v1)
+#define ARRAY_BY_EXTRUDERS1(v1) ARRAY_BY_EXTRUDERS(v1, v1, v1, v1, v1, v1, v1, v1)
 #define ARRAY_BY_HOTENDS(V...) ARRAY_N(HOTENDS, V)
-#define ARRAY_BY_HOTENDS1(v1) ARRAY_BY_HOTENDS(v1, v1, v1, v1, v1, v1)
+#define ARRAY_BY_HOTENDS1(v1) ARRAY_BY_HOTENDS(v1, v1, v1, v1, v1, v1, v1, v1)
 
 #define DO_SWITCH_EXTRUDER (ENABLED(SWITCHING_EXTRUDER) && (DISABLED(SWITCHING_NOZZLE) || SWITCHING_EXTRUDER_SERVO_NR != SWITCHING_NOZZLE_SERVO_NR))
 #define SWITCHING_NOZZLE_TWO_SERVOS defined(SWITCHING_NOZZLE_E1_SERVO_NR)
diff --git a/Marlin/src/module/temperature.cpp b/Marlin/src/module/temperature.cpp
index c9547b3e9..73a91049d 100644
--- a/Marlin/src/module/temperature.cpp
+++ b/Marlin/src/module/temperature.cpp
@@ -101,11 +101,13 @@
 
 #if HOTEND_USES_THERMISTOR
   #if ENABLED(TEMP_SENSOR_1_AS_REDUNDANT)
-    static void* heater_ttbl_map[2] = { (void*)HEATER_0_TEMPTABLE, (void*)HEATER_1_TEMPTABLE };
+    static const void* heater_ttbl_map[2] = { (void*)HEATER_0_TEMPTABLE, (void*)HEATER_1_TEMPTABLE };
     static constexpr uint8_t heater_ttbllen_map[2] = { HEATER_0_TEMPTABLE_LEN, HEATER_1_TEMPTABLE_LEN };
   #else
-    static void* heater_ttbl_map[HOTENDS] = ARRAY_BY_HOTENDS((void*)HEATER_0_TEMPTABLE, (void*)HEATER_1_TEMPTABLE, (void*)HEATER_2_TEMPTABLE, (void*)HEATER_3_TEMPTABLE, (void*)HEATER_4_TEMPTABLE, (void*)HEATER_5_TEMPTABLE);
-    static constexpr uint8_t heater_ttbllen_map[HOTENDS] = ARRAY_BY_HOTENDS(HEATER_0_TEMPTABLE_LEN, HEATER_1_TEMPTABLE_LEN, HEATER_2_TEMPTABLE_LEN, HEATER_3_TEMPTABLE_LEN, HEATER_4_TEMPTABLE_LEN, HEATER_5_TEMPTABLE_LEN);
+    #define NEXT_TEMPTABLE(N) ,HEATER_##N##_TEMPTABLE
+    #define NEXT_TEMPTABLE_LEN(N) ,HEATER_##N##_TEMPTABLE_LEN
+    static const void* heater_ttbl_map[HOTENDS] = ARRAY_BY_HOTENDS(HEATER_0_TEMPTABLE REPEAT_S(1, HOTENDS, NEXT_TEMPTABLE));
+    static constexpr uint8_t heater_ttbllen_map[HOTENDS] = ARRAY_BY_HOTENDS(HEATER_0_TEMPTABLE_LEN REPEAT_S(1, HOTENDS, NEXT_TEMPTABLE_LEN));
   #endif
 #endif
 
diff --git a/Marlin/src/pins/pins.h b/Marlin/src/pins/pins.h
index ce03a3468..920c124a5 100644
--- a/Marlin/src/pins/pins.h
+++ b/Marlin/src/pins/pins.h
@@ -35,7 +35,7 @@
  *    These numbers are the same in any pin mapping.
  */
 
-#define MAX_EXTRUDERS 6
+#define MAX_EXTRUDERS 8
 
 #if   MB(RAMPS_13_EFB, RAMPS_14_EFB, RAMPS_PLUS_EFB, RAMPS_14_RE_ARM_EFB, RAMPS_SMART_EFB, RAMPS_DUO_EFB, RAMPS4DUE_EFB)
   #define IS_RAMPS_EFB
diff --git a/Marlin/src/pins/sensitive_pins.h b/Marlin/src/pins/sensitive_pins.h
index 807ee99e2..180bc8d6f 100644
--- a/Marlin/src/pins/sensitive_pins.h
+++ b/Marlin/src/pins/sensitive_pins.h
@@ -278,9 +278,9 @@
 #endif
 
 #define _E6_CS
+#define _E6_MS1
 #define _E6_MS2
 #define _E6_MS3
-#define _E6_MS4
 
 #if E_NEEDED(6)
   #if PIN_EXISTS(E6_CS) && AXIS_HAS_SPI(E6)
@@ -302,9 +302,9 @@
 #endif
 
 #define _E7_CS
+#define _E7_MS1
+#define _E7_MS2
 #define _E7_MS3
-#define _E7_MS4
-#define _E7_MS5
 
 #if E_NEEDED(7)
   #if PIN_EXISTS(E7_CS) && AXIS_HAS_SPI(E7)
diff --git a/Marlin/src/pins/stm32/pins_BTT_GTR_V1_0.h b/Marlin/src/pins/stm32/pins_BTT_GTR_V1_0.h
index aa2152c84..0500c5d95 100644
--- a/Marlin/src/pins/stm32/pins_BTT_GTR_V1_0.h
+++ b/Marlin/src/pins/stm32/pins_BTT_GTR_V1_0.h
@@ -237,8 +237,8 @@
 #define TEMP_3_PIN         PA3   // T4 <-> E3
 #define TEMP_4_PIN         PF9   // T5 <-> E4
 #define TEMP_5_PIN         PF10  // T6 <-> E5
-//#define TEMP_6_PIN         PF7   // T7 <-> E6
-//#define TEMP_7_PIN         PF5   // T8 <-> E7
+#define TEMP_6_PIN         PF7   // T7 <-> E6
+#define TEMP_7_PIN         PF5   // T8 <-> E7
 
 #define TEMP_BED_PIN       PC0   // T0 <-> Bed
 
@@ -266,8 +266,8 @@
 #define HEATER_3_PIN       PD15  // Heater3
 #define HEATER_4_PIN       PD13  // Heater4
 #define HEATER_5_PIN       PD12  // Heater5
-//#define HEATER_6_PIN       PE13 // Heater6
-//#define HEATER_7_PIN       PI6  // Heater7
+#define HEATER_6_PIN       PE13 // Heater6
+#define HEATER_7_PIN       PI6  // Heater7
 
 #define HEATER_BED_PIN     PA2   // Hotbed
 
diff --git a/buildroot/share/tests/BIGTREE_GTR_V1_0-tests b/buildroot/share/tests/BIGTREE_GTR_V1_0-tests
new file mode 100644
index 000000000..0738a2818
--- /dev/null
+++ b/buildroot/share/tests/BIGTREE_GTR_V1_0-tests
@@ -0,0 +1,39 @@
+#!/usr/bin/env bash
+#
+# Build tests for BigTreeTech GTR 1.0
+#
+
+# exit on first failure
+set -e
+
+restore_configs
+opt_set MOTHERBOARD BOARD_BTT_GTR_V1_0
+opt_set SERIAL_PORT -1
+opt_set EXTRUDERS 8
+opt_set TEMP_SENSOR_1 1
+opt_set TEMP_SENSOR_2 1
+opt_set TEMP_SENSOR_3 1
+opt_set TEMP_SENSOR_4 1
+opt_set TEMP_SENSOR_5 1
+opt_set TEMP_SENSOR_6 1
+opt_set TEMP_SENSOR_7 1
+# Not necessary to enable auto-fan for all extruders to hit problematic code paths
+opt_set E0_AUTO_FAN_PIN PC10
+opt_set E1_AUTO_FAN_PIN PC11
+opt_set E2_AUTO_FAN_PIN PC12
+exec_test $1 $2 "BigTreeTech GTR 8 Extruders with Auto-Fan"
+
+restore_configs
+opt_set MOTHERBOARD BOARD_BTT_GTR_V1_0
+opt_set SERIAL_PORT -1
+opt_set EXTRUDERS 6
+opt_set TEMP_SENSOR_1 1
+opt_set TEMP_SENSOR_2 1
+opt_set TEMP_SENSOR_3 1
+opt_set TEMP_SENSOR_4 1
+opt_set TEMP_SENSOR_5 1
+opt_set NUM_Z_STEPPER_DRIVERS 3
+exec_test $1 $2 "BigTreeTech GTR 6 Extruders Triple Z"
+
+# clean up
+restore_configs
diff --git a/platformio.ini b/platformio.ini
index 405efd862..f69842caf 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -681,13 +681,12 @@ debug_init_break  =
 [env:BIGTREE_GTR_V1_0]
 platform          = ststm32@>=5.7.0
 framework         = arduino
-platform_packages = framework-arduinoststm32@>=3.10700.191028
+platform_packages = framework-arduinoststm32@>=3.107,<4
 board             = BigTree_SKR_Pro
 extra_scripts     = pre:buildroot/share/PlatformIO/scripts/generic_create_variant.py
 build_flags       = ${common.build_flags}
   -DUSBCON -DUSBD_USE_CDC -DUSBD_VID=0x0483 -DUSB_PRODUCT=\"STM32F407IG\"
   -DTARGET_STM32F4 -DSTM32F407IX -DVECT_TAB_OFFSET=0x8000
-
   -IMarlin/src/HAL/HAL_STM32
 lib_deps          =
   U8glib-HAL=https://github.com/MarlinFirmware/U8glib-HAL/archive/bugfix.zip