+rev2 tested

keyboards/alko/cornedeon/keymaps/vial/config.h

@@ -23,7 +23,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define VIAL_UNLOCK_COMBO_COLS {0, 1}
 
 // For master half only when MASTER_LEFT/MASTER_RIGHT using
-#define WAIT_FOR_USB
+//#define WAIT_FOR_USB
 
 /* Select hand configuration */
 

keyboards/alko/cornedeon/keymaps/vial/rules.mk

@@ -13,6 +13,6 @@ COMBO_ENABLE        = yes
 
 QMK_SETTINGS        = no
 
-CAPS_WORD_ENABLE = no
-LAYER_LOCK_ENABLE = no
-REPEAT_KEY_ENABLE = no
+CAPS_WORD_ENABLE    = no
+LAYER_LOCK_ENABLE   = no
+REPEAT_KEY_ENABLE   = no

keyboards/alko/cornedeon/rev2/config.h

@@ -5,8 +5,10 @@
 
 //#define SERIAL_USART_FULL_DUPLEX
 //#define SERIAL_USART_RX_PIN GP2
-#define SERIAL_USART_TX_PIN GP1
+//#define SERIAL_USART_TX_PIN GP1
+#define USE_SERIAL
 //#define SOFT_SERIAL_PIN GP1
+//#define USB_VBUS_PIN GP2
 
 /* RP2040- and hardware-specific config */
 #define RP2040_BOOTLOADER_DOUBLE_TAP_RESET // Activates the double-tap behavior

keyboards/alko/cornedeon/rev2/keyboard.json

@@ -38,7 +38,8 @@
             "pin": "GP8"
         },
         "serial": {
-            "driver": "vendor"
+            "driver": "vendor",
+            "pin": "GP1"
         },
         "transport": {
             "sync": {